1.
Blue Screen of Death
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BSoDs have been present in Windows NT3.1 and all Windows operating systems released afterwards. In the Windows 9x era, incompatible DLLs or bugs in the system kernel could also cause BSoDs. Because of the instability and lack of protection in Windows 9x. The article was about the creation of the first rudimentary task manager in Windows 3. x, engadget later updated its article to correct the mistake. Until Windows Server 2012, BSoDs showed silver text on a blue background with information about current memory values. Windows Server 2012, Windows 8 and Windows 10 use a background instead. Windows 95,98 and ME BSoDs use 80×25 text mode, BSoDs in the Windows NT family use 80×50 text mode on a 720×400 screen. Windows XP BSoDs use the Lucida Console font while the Windows Vista and 7 BSoD uses the Consolas font, Windows 8, Windows Server 2012 use Segoe UI and attempt to render the BSoD at native resolution, otherwise defaulting to 640x480. Windows 10 uses the format as Windows 8 and up. In Windows NT family of operating systems, the screen of death occurs when the kernel or a driver running in kernel mode encounters an error from which it cannot recover. This is usually caused by an illegal operation being performed, the only safe action the operating system can take in this situation is to restart the computer. As a result, data may be lost, as users are not given an opportunity to save data that has not yet been saved to the hard drive. Depending on the code, it may display the address where the problem occurred. Under Windows NT, the second and third sections of the screen may contain information on all loaded drivers and a stack dump, respectively. The driver information is in three columns, the first lists the address of the driver, the second lists the drivers creation date. By default, Windows will create a dump file when a stop error occurs. Depending on the OS version, there may be several formats this can be saved in, the resulting memory dump file may be debugged later, using a kernel debugger. For Windows WinDBG or KD debuggers from Debugging Tools for Windows are used, by default, Windows XP is configured to save only a 64kB minidump when it encounters a stop error, and to then automatically reboot the computer
2.
Software developer
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A software developer is a person concerned with facets of the software development process, including the research, design, programming, and testing of computer software. Other job titles which are used with similar meanings are programmer, software analyst. According to developer Eric Sink, the differences between system design, software development, and programming are more apparent, even more so that developers become systems architects, those who design the multi-leveled architecture or component interactions of a large software system. In a large company, there may be employees whose sole responsibility consists of one of the phases above. In smaller development environments, a few people or even an individual might handle the complete process. The word software was coined as a prank as early as 1953, before this time, computers were programmed either by customers, or the few commercial computer vendors of the time, such as UNIVAC and IBM. The first company founded to provide products and services was Computer Usage Company in 1955. The software industry expanded in the early 1960s, almost immediately after computers were first sold in mass-produced quantities, universities, government, and business customers created a demand for software. Many of these programs were written in-house by full-time staff programmers, some were distributed freely between users of a particular machine for no charge. Others were done on a basis, and other firms such as Computer Sciences Corporation started to grow. The computer/hardware makers started bundling operating systems, systems software and programming environments with their machines, new software was built for microcomputers, so other manufacturers including IBM, followed DECs example quickly, resulting in the IBM AS/400 amongst others. The industry expanded greatly with the rise of the computer in the mid-1970s. In the following years, it created a growing market for games, applications. DOS, Microsofts first operating system product, was the dominant operating system at the time, by 2014 the role of cloud developer had been defined, in this context, one definition of a developer in general was published, Developers make software for the world to use. The job of a developer is to crank out code -- fresh code for new products, code fixes for maintenance, code for business logic, bus factor Software Developer description from the US Department of Labor
3.
University of California, Berkeley
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The University of California, Berkeley, is a public research university located in Berkeley, California. In 1960s, UC Berkeley was particularly noted for the Free Speech Movement as well as the Anti-Vietnam War Movement led by its students. S, Department of Energy, and is home to many world-renowned research institutes and organizations including Mathematical Sciences Research Institute and Space Sciences Laboratory. Faculty member J. R. Oppenheimer, the father of the atomic bomb, Lawrence Livermore Lab also discovered or co-discovered six chemical elements. The Academic Ranking of World Universities also ranks the University of California, Berkeley, third in the world overall, in 1866, the private College of California purchased the land comprising the current Berkeley campus. Ten faculty members and almost 40 students made up the new University of California when it opened in Oakland in 1869, billings was a trustee of the College of California and suggested that the college be named in honor of the Anglo-Irish philosopher George Berkeley. In 1870, Henry Durant, the founder of the College of California, with the completion of North and South Halls in 1873, the university relocated to its Berkeley location with 167 male and 22 female students and held its first classes. In 1905, the University Farm was established near Sacramento, ultimately becoming the University of California, by the 1920s, the number of campus buildings had grown substantially, and included twenty structures designed by architect John Galen Howard. Robert Gordon Sproul served as president from 1930 to 1958, by 1942, the American Council on Education ranked UC Berkeley second only to Harvard University in the number of distinguished departments. During World War II, following Glenn Seaborgs then-secret discovery of plutonium, UC Berkeley physics professor J. Robert Oppenheimer was named scientific head of the Manhattan Project in 1942. Along with the Lawrence Berkeley National Laboratory, Berkeley is now a partner in managing two other labs, Los Alamos National Laboratory and Lawrence Livermore National Laboratory, originally, military training was compulsory for male undergraduates, and Berkeley housed an armory for that purpose. In 1917, Berkeleys ROTC program was established, and its School of Military Aeronautics trained future pilots, including Jimmy Doolittle, both Robert McNamara and Frederick C. Weyand graduated from UC Berkeleys ROTC program, earning B. A. degrees in 1937 and 1938, in 1926, future fleet admiral Chester W. Nimitz established the first Naval Reserve Officers Training Corps unit at Berkeley. The Board of Regents ended compulsory military training at Berkeley in 1962, during the McCarthy era in 1949, the Board of Regents adopted an anti-communist loyalty oath. A number of faculty members objected and were dismissed, ten years passed before they were reinstated with back pay, in 1952, the University of California became an entity separate from the Berkeley campus. Each campus was given autonomy and its own Chancellor. Then-president Sproul assumed presidency of the entire University of California system, Berkeley gained a reputation for student activism in the 1960s with the Free Speech Movement of 1964 and opposition to the Vietnam War. In the highly publicized Peoples Park protest in 1969, students and the school conflicted over use of a plot of land, then governor of California Ronald Reagan called the Berkeley campus a haven for communist sympathizers, protesters, and sex deviants. Modern students at Berkeley are less active, with a greater percentage of moderates and conservatives
4.
Programming language
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A programming language is a formal computer language designed to communicate instructions to a machine, particularly a computer. Programming languages can be used to programs to control the behavior of a machine or to express algorithms. From the early 1800s, programs were used to direct the behavior of such as Jacquard looms. Thousands of different programming languages have created, mainly in the computer field. Many programming languages require computation to be specified in an imperative form while other languages use forms of program specification such as the declarative form. The description of a language is usually split into the two components of syntax and semantics. Some languages are defined by a document while other languages have a dominant implementation that is treated as a reference. Some languages have both, with the language defined by a standard and extensions taken from the dominant implementation being common. A programming language is a notation for writing programs, which are specifications of a computation or algorithm, some, but not all, authors restrict the term programming language to those languages that can express all possible algorithms. For example, PostScript programs are created by another program to control a computer printer or display. More generally, a language may describe computation on some, possibly abstract. It is generally accepted that a specification for a programming language includes a description, possibly idealized. In most practical contexts, a programming language involves a computer, consequently, abstractions Programming languages usually contain abstractions for defining and manipulating data structures or controlling the flow of execution. Expressive power The theory of computation classifies languages by the computations they are capable of expressing, all Turing complete languages can implement the same set of algorithms. ANSI/ISO SQL-92 and Charity are examples of languages that are not Turing complete, markup languages like XML, HTML, or troff, which define structured data, are not usually considered programming languages. Programming languages may, however, share the syntax with markup languages if a computational semantics is defined, XSLT, for example, is a Turing complete XML dialect. Moreover, LaTeX, which is used for structuring documents. The term computer language is used interchangeably with programming language
5.
C (programming language)
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C was originally developed by Dennis Ritchie between 1969 and 1973 at Bell Labs, and used to re-implement the Unix operating system. C has been standardized by the American National Standards Institute since 1989, C is an imperative procedural language. Therefore, C was useful for applications that had formerly been coded in assembly language. Despite its low-level capabilities, the language was designed to encourage cross-platform programming, a standards-compliant and portably written C program can be compiled for a very wide variety of computer platforms and operating systems with few changes to its source code. The language has become available on a wide range of platforms. In C, all code is contained within subroutines, which are called functions. Function parameters are passed by value. Pass-by-reference is simulated in C by explicitly passing pointer values, C program source text is free-format, using the semicolon as a statement terminator and curly braces for grouping blocks of statements. The C language also exhibits the characteristics, There is a small, fixed number of keywords, including a full set of flow of control primitives, for, if/else, while, switch. User-defined names are not distinguished from keywords by any kind of sigil, There are a large number of arithmetical and logical operators, such as +, +=, ++, &, ~, etc. More than one assignment may be performed in a single statement, function return values can be ignored when not needed. Typing is static, but weakly enforced, all data has a type, C has no define keyword, instead, a statement beginning with the name of a type is taken as a declaration. There is no function keyword, instead, a function is indicated by the parentheses of an argument list, user-defined and compound types are possible. Heterogeneous aggregate data types allow related data elements to be accessed and assigned as a unit, array indexing is a secondary notation, defined in terms of pointer arithmetic. Unlike structs, arrays are not first-class objects, they cannot be assigned or compared using single built-in operators, There is no array keyword, in use or definition, instead, square brackets indicate arrays syntactically, for example month. Enumerated types are possible with the enum keyword and they are not tagged, and are freely interconvertible with integers. Strings are not a data type, but are conventionally implemented as null-terminated arrays of characters. Low-level access to memory is possible by converting machine addresses to typed pointers
6.
Unix
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Among these is Apples macOS, which is the Unix version with the largest installed base as of 2014. Many Unix-like operating systems have arisen over the years, of which Linux is the most popular, Unix was originally meant to be a convenient platform for programmers developing software to be run on it and on other systems, rather than for non-programmer users. The system grew larger as the system started spreading in academic circles, as users added their own tools to the system. Unix was designed to be portable, multi-tasking and multi-user in a time-sharing configuration and these concepts are collectively known as the Unix philosophy. By the early 1980s users began seeing Unix as a universal operating system. Under Unix, the system consists of many utilities along with the master control program. To mediate such access, the kernel has special rights, reflected in the division between user space and kernel space, the microkernel concept was introduced in an effort to reverse the trend towards larger kernels and return to a system in which most tasks were completed by smaller utilities. In an era when a standard computer consisted of a disk for storage and a data terminal for input and output. However, modern systems include networking and other new devices, as graphical user interfaces developed, the file model proved inadequate to the task of handling asynchronous events such as those generated by a mouse. In the 1980s, non-blocking I/O and the set of inter-process communication mechanisms were augmented with Unix domain sockets, shared memory, message queues, and semaphores. In microkernel implementations, functions such as network protocols could be moved out of the kernel, Multics introduced many innovations, but had many problems. Frustrated by the size and complexity of Multics but not by the aims and their last researchers to leave Multics, Ken Thompson, Dennis Ritchie, M. D. McIlroy, and J. F. Ossanna, decided to redo the work on a much smaller scale. The name Unics, a pun on Multics, was suggested for the project in 1970. Peter H. Salus credits Peter Neumann with the pun, while Brian Kernighan claims the coining for himself, in 1972, Unix was rewritten in the C programming language. Bell Labs produced several versions of Unix that are referred to as Research Unix. In 1975, the first source license for UNIX was sold to faculty at the University of Illinois Department of Computer Science, UIUC graduate student Greg Chesson was instrumental in negotiating the terms of this license. During the late 1970s and early 1980s, the influence of Unix in academic circles led to adoption of Unix by commercial startups, including Sequent, HP-UX, Solaris, AIX. In the late 1980s, AT&T Unix System Laboratories and Sun Microsystems developed System V Release 4, in the 1990s, Unix-like systems grew in popularity as Linux and BSD distributions were developed through collaboration by a worldwide network of programmers
7.
Free software
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The right to study and modify software entails availability of the software source code to its users. This right is conditional on the person actually having a copy of the software. Richard Stallman used the existing term free software when he launched the GNU Project—a collaborative effort to create a freedom-respecting operating system—and the Free Software Foundation. The FSFs Free Software Definition states that users of software are free because they do not need to ask for permission to use the software. Free software thus differs from proprietary software, such as Microsoft Office, Google Docs, Sheets, and Slides or iWork from Apple, which users cannot study, change, freeware, which is a category of freedom-restricting proprietary software that does not require payment for use. For computer programs that are covered by law, software freedom is achieved with a software license. Software that is not covered by law, such as software in the public domain, is free if the source code is in the public domain. Proprietary software, including freeware, use restrictive software licences or EULAs, Users are thus prevented from changing the software, and this results in the user relying on the publisher to provide updates, help, and support. This situation is called vendor lock-in, Users often may not reverse engineer, modify, or redistribute proprietary software. Other legal and technical aspects, such as patents and digital rights management may restrict users in exercising their rights. Free software may be developed collaboratively by volunteer computer programmers or by corporations, as part of a commercial, from the 1950s up until the early 1970s, it was normal for computer users to have the software freedoms associated with free software, which was typically public domain software. Software was commonly shared by individuals who used computers and by manufacturers who welcomed the fact that people were making software that made their hardware useful. Organizations of users and suppliers, for example, SHARE, were formed to exchange of software. As software was written in an interpreted language such as BASIC. Software was also shared and distributed as printed source code in computer magazines and books, in United States vs. IBM, filed January 17,1969, the government charged that bundled software was anti-competitive. While some software might always be free, there would henceforth be an amount of software produced primarily for sale. In the 1970s and early 1980s, the industry began using technical measures to prevent computer users from being able to study or adapt the software as they saw fit. In 1980, copyright law was extended to computer programs, Software development for the GNU operating system began in January 1984, and the Free Software Foundation was founded in October 1985
8.
Software release life cycle
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Usage of the alpha/beta test terminology originated at IBM. As long ago as the 1950s, IBM used similar terminology for their hardware development, a test was the verification of a new product before public announcement. B test was the verification before releasing the product to be manufactured, C test was the final test before general availability of the product. Martin Belsky, a manager on some of IBMs earlier software projects claimed to have invented the terminology, IBM dropped the alpha/beta terminology during the 1960s, but by then it had received fairly wide notice. The usage of beta test to refer to testing done by customers was not done in IBM, rather, IBM used the term field test. Pre-alpha refers to all activities performed during the project before formal testing. These activities can include requirements analysis, software design, software development, in typical open source development, there are several types of pre-alpha versions. Milestone versions include specific sets of functions and are released as soon as the functionality is complete, the alpha phase of the release life cycle is the first phase to begin software testing. In this phase, developers generally test the software using white-box techniques, additional validation is then performed using black-box or gray-box techniques, by another testing team. Moving to black-box testing inside the organization is known as alpha release, alpha software can be unstable and could cause crashes or data loss. Alpha software may not contain all of the features that are planned for the final version, in general, external availability of alpha software is uncommon in proprietary software, while open source software often has publicly available alpha versions. The alpha phase usually ends with a freeze, indicating that no more features will be added to the software. At this time, the software is said to be feature complete, Beta, named after the second letter of the Greek alphabet, is the software development phase following alpha. Software in the stage is also known as betaware. Beta phase generally begins when the software is complete but likely to contain a number of known or unknown bugs. Software in the phase will generally have many more bugs in it than completed software, as well as speed/performance issues. The focus of beta testing is reducing impacts to users, often incorporating usability testing, the process of delivering a beta version to the users is called beta release and this is typically the first time that the software is available outside of the organization that developed it. Beta version software is useful for demonstrations and previews within an organization
9.
PDP-11
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The PDP-11 is a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 had several innovative features, and was easier to program than its predecessors through the additional general-purpose registers. The PDP-11 replaced the PDP-8 in many applications, although both product lines lived in parallel for more than 10 years. In total, around 600,000 PDP-11s of all models were sold and its successor in the mid-range minicomputer niche was the 32-bit VAX-11, named as a nod to the PDP-11s popularity. The PDP-11 is considered by experts to be the most popular minicomputer ever. Design features of the PDP-11 influenced the design of most late-1970s computer systems including the Intel x86, design features of PDP-11 operating systems, as well as other operating systems from Digital Equipment, influenced the design of other operating systems such as CP/M and hence also MS-DOS. For a decade, the PDP-11 was the smallest system that could run Unix and it is commonly stated that the C programming language took advantage of several low-level PDP-11–dependent programming features, albeit not originally by design. In 1967–68, DEC engineers designed a 16-bit, word-addressed machine, management cancelled the project and some of the engineers later left DEC and produced it as the Data General Nova. A subsequent effort, code-named Desk Calculator, looked at a variety of options before choosing what became the 16-bit PDP-11, DECs previous PDP-8 and PDP-9 had 12- and 18-bit words, the PDP-11 family was announced in January 1970 and shipments began early that year. DEC sold over 170,000 PDP-11s in the 1970s, initially manufactured of small-scale transistor–transistor logic, a single-board large scale integration version of the processor was developed in 1975. A two-or-three-chip processor, the J-11 was developed in 1979, the last models of the PDP-11 line were the PDP-11/94 and -11/93 introduced in 1990. The PDP-11 processor architecture has an orthogonal instruction set. For example, instead of such as load and store. More complex instructions such as add likewise can have memory, register, input, most operands can apply any of eight addressing modes to eight registers. The addressing modes provide register, immediate, absolute, relative, deferred, and indexed addressing, use of relative addressing lets a machine-language program be position-independent. Early models of the PDP-11 had no dedicated bus for input/output, an input/output device determined the memory addresses to which it would respond, and specified its own interrupt vector and interrupt priority. DEC openly published the basic Unibus specifications, even offering prototyping bus interface circuit boards, the Unibus made the PDP-11 suitable for custom peripherals. Higher-performance members of the PDP-11 family, starting with the PDP-11/45 Unibus and 11/83 Q-bus systems, instead, memory was interfaced by dedicated circuitry and space in the CPU cabinet, while the Unibus continued to be used for I/O only
10.
VAX
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VAX is a discontinued instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. The VAX-11/780, introduced on October 25,1977, was the first of a range of popular, a 32-bit system with a CISC architecture based on DECs earlier PDP-11, VAX was designed to extend or replace DECs various PDP ISAs. The VAX architectures primary features were virtual addressing and its instruction set. Later versions offloaded the compatibility mode and some of the less used CISC instructions to emulation in the system software. The VAX instruction set was designed to be powerful and orthogonal, when it was introduced, many programs were written in assembly language, so having a programmer-friendly instruction set was important. In time, as programs were written in higher-level language, the instruction set became less visible. One unusual aspect of the VAX instruction set is the presence of register masks at the start of each subprogram and these are arbitrary bit patterns that specify, when control is passed to the subprogram, which registers are to be preserved. Since register masks are a form of data embedded within the executable code and this can complicate optimization techniques that are applied on machine code. The native VAX operating system is Digitals VAX/VMS, the VAX architecture and OpenVMS operating system were engineered concurrently to take maximum advantage of each other, as was the initial implementation of the VAXcluster facility. Other VAX operating systems have included various releases of BSD UNIX up to 4. 3BSD, Ultrix-32, VAXELN, more recently, NetBSD and OpenBSD support various VAX models and some work has been done on porting Linux to the VAX architecture. The first VAX model sold was the VAX-11/780, which was introduced on October 25,1977 at the Digital Equipment Corporations Annual Meeting of Shareholders, bill Strecker, C. Gordon Bells doctoral student at Carnegie Mellon University, was responsible for the architecture. Many different models with different prices, performance levels, and capacities were subsequently created, VAX superminicomputers were very popular in the early 1980s. For a while the VAX-11/780 was used as a standard in CPU benchmarks, the actual number of instructions executed in 1 second was about 500,000, which led to complaints of marketing exaggeration. The result was the definition of a VAX MIPS, the speed of a VAX-11/780, within the Digital community the term VUP was the more common term, because MIPS do not compare well across different architectures. The related term cluster VUPs was informally used to describe the performance of a VAXcluster. The VAX-11/780 included a subordinate stand-alone LSI-11 computer that performed microcode load, booting and this was dropped from subsequent VAX models. Enterprising VAX-11/780 users could therefore run three different Digital Equipment Corporation operating systems, VMS on the VAX processor, and either RSX-11M or RT-11 on the LSI-11, the VAX went through many different implementations. The original VAX 11/780 was implemented in TTL and filled a cabinet with a single CPU
11.
Intel 80386
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The Intel 80386, also known as i386 or just 386, is a 32-bit microprocessor introduced in 1985. The first versions had 275,000 transistors and were the CPU of many workstations, the 32-bit 80386 can correctly execute most code intended for the earlier 16-bit processors such as 8088 and 80286 that were ubiquitous in early PCs. Over the years, successively newer implementations of the architecture have become several hundreds of times faster than the original 80386. A33 MHz 80386 was reportedly measured to operate at about 11.4 MIPS, the 80386 was introduced in October 1985, while manufacturing of the chips in significant quantities commenced in June 1986. Mainboards for 80386-based computer systems were cumbersome and expensive at first, in May 2006, Intel announced that 80386 production would stop at the end of September 2007. Although it had long been obsolete as a personal computer CPU, Intel, such systems using an 80386 or one of many derivatives are common in aerospace technology and electronic musical instruments, among others. Some mobile phones used the 80386 processor, such as BlackBerry 950. The processor was a significant evolution in the x86 architecture, the predecessor of the 80386 was the Intel 80286, a 16-bit processor with a segment-based memory management and protection system. The 80386 added a 32-bit architecture and a translation unit. It also offered support for register debugging, the 80386 featured three operating modes, real mode, protected mode and virtual mode. The protected mode which debuted in the 286 was extended to allow the 386 to address up to 4 GB of memory, the all new virtual 8086 mode made it possible to run one or more real mode programs in a protected environment, although some programs were not compatible. Several new instructions have been added to 386, BSF, BSR, BT, BTS, BTR, BTC, CDQ, CWDE, LFS, LGS, LSS, MOVSX, MOVZX, SETcc, SHLD, SHRD. Two new segment registers have been added for general purpose programs, debug registers DR0-DR7 were added for hardware breakpoints. New forms of MOV instruction are used to access them, chief architect in the development of the 80386 was John H. Crawford. He was responsible for extending the 80286 architecture and instruction set to 32-bit, the 80486 and P5 Pentium line of processors were descendants of the 80386 design. The following data types are supported and thus implemented by one or more 80386 machine instructions. Bit, bit field and bit string, 8-bit integer, either signed or unsigned. 16-bit integer, either signed or unsigned, 32-bit integer, either signed or unsigned
12.
Kernel (operating system)
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The kernel is a computer program that is the core of a computers operating system, with complete control over everything in the system. It is the first program loaded on start-up and it handles the rest of start-up as well as input/output requests from software, translating them into data-processing instructions for the central processing unit. It handles memory and peripherals like keyboards, monitors, printers, the critical code of the kernel is usually loaded into a protected area of memory, which prevents it from being overwritten by applications or other, more minor parts of the operating system. The kernel performs its tasks, such as running processes and handling interrupts, in contrast, everything a user does is in user space, writing text in a text editor, running programs in a GUI, etc. This separation prevents user data and kernel data from interfering with other and causing instability. The kernels interface is an abstraction layer. When a process makes requests of the kernel, it is called a system call, Kernel designs differ in how they manage these system calls and resources. A monolithic kernel runs all the operating instructions in the same address space. A microkernel runs most processes in space, for modularity. The kernel takes responsibility for deciding at any time which of the running programs should be allocated to the processor or processors. Random-access memory Random-access memory is used to both program instructions and data. Typically, both need to be present in memory in order for a program to execute, often multiple programs will want access to memory, frequently demanding more memory than the computer has available. The kernel is responsible for deciding which memory each process can use, input/output devices I/O devices include such peripherals as keyboards, mice, disk drives, printers, network adapters, and display devices. The kernel allocates requests from applications to perform I/O to an appropriate device, key aspects necessary in resource management are the definition of an execution domain and the protection mechanism used to mediate the accesses to the resources within a domain. Kernels also usually provide methods for synchronization and communication between processes called inter-process communication, finally, a kernel must provide running programs with a method to make requests to access these facilities. The kernel has full access to the memory and must allow processes to safely access this memory as they require it. Often the first step in doing this is virtual addressing, usually achieved by paging and/or segmentation, virtual addressing allows the kernel to make a given physical address appear to be another address, the virtual address. This allows every program to behave as if it is the one running
13.
Monolithic kernel
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A monolithic kernel is an operating system architecture where the entire operating system is working in kernel space and is alone in supervisor mode. The monolithic model differs from other operating system architectures in that it defines a high-level virtual interface over computer hardware. A set of primitives or system calls implement all operating system such as process management, concurrency. Device drivers can be added to the kernel as modules and this modularity of the operating system is at the binary level and not at the architecture level. Modular monolithic operating systems are not to be confused with the level of modularity inherent in Server-Client operating systems which use microkernels. Practically speaking, dynamically loading modules is simply a more flexible way of handling the operating system image at runtime — as opposed to rebooting with a different operating system image, the modules allow easy extension of the operating systems capabilities as required. Dynamically loadable modules incur a small overhead when compared to building the module into the system image. Namely, an unloaded module need not be stored in random access memory
14.
User interface
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The user interface, in the industrial design field of human–computer interaction, is the space where interactions between humans and machines occur. Examples of this concept of user interfaces include the interactive aspects of computer operating systems, hand tools, heavy machinery operator controls. The design considerations applicable when creating user interfaces are related to or involve such disciplines as ergonomics and psychology. Generally, the goal of user interface design is to produce a user interface makes it easy, efficient. This generally means that the needs to provide minimal input to achieve the desired output. Other terms for user interface are man–machine interface and when the machine in question is a computer human–computer interface, the user interface or human–machine interface is the part of the machine that handles the human–machine interaction. Membrane switches, rubber keypads and touchscreens are examples of the part of the Human Machine Interface which we can see. In complex systems, the interface is typically computerized. The term human–computer interface refers to this kind of system, in the context of computing the term typically extends as well to the software dedicated to control the physical elements used for human-computer interaction. The engineering of the interfaces is enhanced by considering ergonomics. The corresponding disciplines are human factors engineering and usability engineering, which is part of systems engineering, tools used for incorporating human factors in the interface design are developed based on knowledge of computer science, such as computer graphics, operating systems, programming languages. Nowadays, we use the graphical user interface for human–machine interface on computers. There is a difference between a user interface and an interface or a human–machine interface. A human-machine interface is typically local to one machine or piece of equipment, an operator interface is the interface method by which multiple equipment that are linked by a host control system is accessed or controlled. The system may expose several user interfaces to serve different kinds of users, for example, a computerized library database might provide two user interfaces, one for library patrons and the other for library personnel. The user interface of a system, a vehicle or an industrial installation is sometimes referred to as the human–machine interface. HMI is a modification of the original term MMI, in practice, the abbreviation MMI is still frequently used although some may claim that MMI stands for something different now. Another abbreviation is HCI, but is commonly used for human–computer interaction
15.
Command-line interface
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A program which handles the interface is called a command language interpreter or shell. The interface is implemented with a command line shell, which is a program that accepts commands as text input. Command-line interfaces to computer operating systems are widely used by casual computer users. Alternatives to the line include, but are not limited to text user interface menus, keyboard shortcuts. Examples of this include the Windows versions 1,2,3,3.1, and 3.11, DosShell, and Mouse Systems PowerPanel. Command-line interfaces are preferred by more advanced computer users, as they often provide a more concise. Programs with command-line interfaces are generally easier to automate via scripting, a program that implements such a text interface is often called a command-line interpreter, command processor or shell. Under most operating systems, it is possible to replace the shell program with alternatives, examples include 4DOS for DOS, 4OS2 for OS/2. For example, the default Windows GUI is a program named EXPLORER. EXE. These programs are shells, but not CLIs, application programs may also have command line interfaces. When a program is launched from an OS command line shell, interactive command line sessions, After launch, a program may provide an operator with an independent means to enter commands in the form of text. OS inter-process communication, Most operating systems support means of inter-process communication, Command lines from client processes may be redirected to a CLI program by one of these methods. Some applications support only a CLI, presenting a CLI prompt to the user, Some examples of CLI-only applications are, DEBUG Diskpart Ed Edlin Fdisk Ping Some computer programs support both a CLI and a GUI. In some cases, a GUI is simply a wrapper around a separate CLI executable file, in other cases, a program may provide a CLI as an optional alternative to its GUI. CLIs and GUIs often support different functionality, for example, all features of MATLAB, a numerical analysis computer program, are available via the CLI, whereas the MATLAB GUI exposes only a subset of features. The early Sierra games, like the first three Kings Quest games, used commands from a command line to move the character around in the graphic window. Early computer systems often used teleprinter machines as the means of interaction with a human operator, the computer became one end of the human-to-human teleprinter model. So instead of a human communicating with another human over a teleprinter, in time, the actual mechanical teleprinter was replaced by a glass tty, and then by a smart terminal
16.
Software license
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A software license is a legal instrument governing the use or redistribution of software. Under United States copyright law all software is copyright protected, in code as also object code form. The only exception is software in the public domain, most distributed software can be categorized according to its license type. Two common categories for software under copyright law, and therefore with licenses which grant the licensee specific rights, are proprietary software and free, unlicensed software outside the copyright protection is either public domain software or software which is non-distributed, non-licensed and handled as internal business trade secret. Contrary to popular belief, distributed unlicensed software is copyright protected. Examples for this are unauthorized software leaks or software projects which are placed on public software repositories like GitHub without specified license. As voluntarily handing software into the domain is problematic in some international law domains, there are also licenses granting PD-like rights. Therefore, the owner of a copy of software is legally entitled to use that copy of software. Hence, if the end-user of software is the owner of the respective copy, as many proprietary licenses only enumerate the rights that the user already has under 17 U. S. C. §117, and yet proclaim to take away from the user. Proprietary software licenses often proclaim to give software publishers more control over the way their software is used by keeping ownership of each copy of software with the software publisher. The form of the relationship if it is a lease or a purchase, for example UMG v. Augusto or Vernor v. Autodesk. The ownership of goods, like software applications and video games, is challenged by licensed. The Swiss based company UsedSoft innovated the resale of business software and this feature of proprietary software licenses means that certain rights regarding the software are reserved by the software publisher. Therefore, it is typical of EULAs to include terms which define the uses of the software, the most significant effect of this form of licensing is that, if ownership of the software remains with the software publisher, then the end-user must accept the software license. In other words, without acceptance of the license, the end-user may not use the software at all, one example of such a proprietary software license is the license for Microsoft Windows. The most common licensing models are per single user or per user in the appropriate volume discount level, Licensing per concurrent/floating user also occurs, where all users in a network have access to the program, but only a specific number at the same time. Another license model is licensing per dongle which allows the owner of the dongle to use the program on any computer, Licensing per server, CPU or points, regardless the number of users, is common practice as well as site or company licenses
17.
Operating system
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An operating system is system software that manages computer hardware and software resources and provides common services for computer programs. All computer programs, excluding firmware, require a system to function. Operating systems are found on many devices that contain a computer – from cellular phones, the dominant desktop operating system is Microsoft Windows with a market share of around 83. 3%. MacOS by Apple Inc. is in place, and the varieties of Linux is in third position. Linux distributions are dominant in the server and supercomputing sectors, other specialized classes of operating systems, such as embedded and real-time systems, exist for many applications. A single-tasking system can run one program at a time. Multi-tasking may be characterized in preemptive and co-operative types, in preemptive multitasking, the operating system slices the CPU time and dedicates a slot to each of the programs. Unix-like operating systems, e. g. Solaris, Linux, cooperative multitasking is achieved by relying on each process to provide time to the other processes in a defined manner. 16-bit versions of Microsoft Windows used cooperative multi-tasking, 32-bit versions of both Windows NT and Win9x, used preemptive multi-tasking. Single-user operating systems have no facilities to distinguish users, but may allow multiple programs to run in tandem, a distributed operating system manages a group of distinct computers and makes them appear to be a single computer. The development of networked computers that could be linked and communicate with each other gave rise to distributed computing, distributed computations are carried out on more than one machine. When computers in a work in cooperation, they form a distributed system. The technique is used both in virtualization and cloud computing management, and is common in large server warehouses, embedded operating systems are designed to be used in embedded computer systems. They are designed to operate on small machines like PDAs with less autonomy and they are able to operate with a limited number of resources. They are very compact and extremely efficient by design, Windows CE and Minix 3 are some examples of embedded operating systems. A real-time operating system is a system that guarantees to process events or data by a specific moment in time. A real-time operating system may be single- or multi-tasking, but when multitasking, early computers were built to perform a series of single tasks, like a calculator. Basic operating system features were developed in the 1950s, such as resident monitor functions that could run different programs in succession to speed up processing
18.
Unix-like
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A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-like application is one that behaves like the corresponding Unix command or shell, there is no standard for defining the term, and some difference of opinion is possible as to the degree to which a given operating system or application is Unix-like. The Open Group owns the UNIX trademark and administers the Single UNIX Specification and they do not approve of the construction Unix-like, and consider it a misuse of their trademark. Other parties frequently treat Unix as a genericized trademark, in 2007, Wayne R. Gray sued to dispute the status of UNIX as a trademark, but lost his case, and lost again on appeal, with the court upholding the trademark and its ownership. Unix-like systems started to appear in the late 1970s and early 1980s, many proprietary versions, such as Idris, UNOS, Coherent, and UniFlex, aimed to provide businesses with the functionality available to academic users of UNIX. These largely displaced the proprietary clones, growing incompatibility among these systems led to the creation of interoperability standards, including POSIX and the Single UNIX Specification. Various free, low-cost, and unrestricted substitutes for UNIX emerged in the 1980s and 1990s, including 4. 4BSD, Linux, some of these have in turn been the basis for commercial Unix-like systems, such as BSD/OS and OS X. The various BSD variants are notable in that they are in fact descendants of UNIX, however, the BSD code base has evolved since then, replacing all of the AT&T code. Since the BSD variants are not certified as compliant with the Single UNIX Specification, dennis Ritchie, one of the original creators of Unix, expressed his opinion that Unix-like systems such as Linux are de facto Unix systems. Eric S. Raymond and Rob Landley have suggested there are three kinds of Unix-like systems, Genetic UNIX Those systems with a historical connection to the AT&T codebase. Most commercial UNIX systems fall into this category, so do the BSD systems, which are descendants of work done at the University of California, Berkeley in the late 1970s and early 1980s. Some of these systems have no original AT&T code but can trace their ancestry to AT&T designs. Trademark or branded UNIX These systems—largely commercial in nature—have been determined by the Open Group to meet the Single UNIX Specification and are allowed to carry the UNIX name, many ancient UNIX systems no longer meet this definition. Around 2001, Linux was given the opportunity to get a certification including free help from the POSIX chair Andrew Josey for the price of one dollar. Some non-Unix-like operating systems provide a Unix-like compatibility layer, with degrees of Unix-like functionality. IBM z/OSs UNIX System Services is sufficiently complete to be certified as trademark UNIX, cygwin and MSYS both provide a GNU environment on top of the Microsoft Windows user API, sufficient for most common open source software to be compiled and run. Subsystem for Unix-based Applications provides Unix-like functionality as a Windows NT subsystem, Windows Subsystem for Linux provides a Linux-compatible kernel interface developed by Microsoft and containing no Linux code, with Ubuntu user-mode binaries running on top of it
19.
Source code
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In computing, source code is any collection of computer instructions, possibly with comments, written using a human-readable programming language, usually as ordinary text. The source code of a program is designed to facilitate the work of computer programmers. The source code is often transformed by an assembler or compiler into binary machine code understood by the computer, the machine code might then be stored for execution at a later time. Alternatively, source code may be interpreted and thus immediately executed, most application software is distributed in a form that includes only executable files. If the source code were included it would be useful to a user, programmer or a system administrator, the Linux Information Project defines source code as, Source code is the version of software as it is originally written by a human in plain text. The notion of source code may also be more broadly, to include machine code and notations in graphical languages. It is therefore so construed as to include code, very high level languages. Often there are several steps of program translation or minification between the source code typed by a human and an executable program. The earliest programs for stored-program computers were entered in binary through the front panel switches of the computer and this first-generation programming language had no distinction between source code and machine code. When IBM first offered software to work with its machine, the code was provided at no additional charge. At that time, the cost of developing and supporting software was included in the price of the hardware, for decades, IBM distributed source code with its software product licenses, until 1983. Most early computer magazines published source code as type-in programs, Source code can also be stored in a database or elsewhere. The source code for a piece of software may be contained in a single file or many files. Though the practice is uncommon, a source code can be written in different programming languages. For example, a program written primarily in the C programming language, in some languages, such as Java, this can be done at run time. The code base of a programming project is the larger collection of all the source code of all the computer programs which make up the project. It has become practice to maintain code bases in version control systems. Moderately complex software customarily requires the compilation or assembly of several, sometimes dozens or even hundreds, in these cases, instructions for compilations, such as a Makefile, are included with the source code
20.
FreeBSD
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FreeBSD is a free and open source Unix-like operating system descended from Research Unix via the Berkeley Software Distribution. Although for legal reasons FreeBSD cannot use the Unix trademark, it is a descendant of BSD. FreeBSD has similarities with Linux, with two differences in scope and licensing, FreeBSD maintains a complete operating system, i. e. The FreeBSD project includes a security team overseeing all software shipped in the base distribution, a wide range of additional third-party applications may be installed using the pkgng package management system or the FreeBSD Ports, or by directly compiling source code. FreeBSDs roots go back to the University of California, Berkeley, the university acquired a UNIX source license from AT&T. The BSD project was founded in 1976 by Bill Joy, but since BSD contained code from AT&T Unix, all recipients had to get a license from AT&T first in order to use BSD. In June 1989, Networking Release 1 or simply Net-1 – the first public version of BSD – was released, after releasing Net-1, Keith Bostic, a developer of BSD, suggested replacing all AT&T code with freely-redistributable code under the original BSD license. Work on replacing AT&T code began and, after 18 months, however, six files containing AT&T code remained in the kernel. The BSD developers decided to release the Networking Release 2 without those six files and they released 386BSD via an anonymous FTP server. The first version of FreeBSD was released on November 1993, in the early days of the projects inception, a company named Walnut Creek CDROM, upon the suggestion of the two FreeBSD developers, agreed to release the operating system on CD-ROM. By 1997, FreeBSD was Walnut Creeks most successful product, the company itself later renamed to The FreeBSD Mall and later iXSystems. Today, FreeBSD is used by many IT companies such as IBM, Nokia, Juniper Networks, certain parts of Apples Mac OS X operating system are based on FreeBSD. The PlayStation 3 operating system also borrows certain components from FreeBSD, netflix, WhatsApp, and FlightAware are also examples of big, successful and heavily network-oriented companies which are running FreeBSD. 386BSD and FreeBSD were both derived from 1992s BSD release, in January 1992, BSDi started to release BSD/386, later called BSD/OS, an operating system similar to FreeBSD and based on 1992s BSD release. AT&T filed a lawsuit against BSDi and alleged distribution of AT&T source code in violation of license agreements, the lawsuit was settled out of court and the exact terms were not all disclosed. The only one that became public was that BSDi would migrate their source base to the newer 4. 4BSD-Lite sources, Although not involved in the litigation, it was suggested to FreeBSD that they should also move to 4. 4BSD-Lite. FreeBSD2.0, which was released on November 1994, was the first version of FreeBSD without any code from AT&T, Desktop Although FreeBSD does not install the X Window System by default, it is available in the FreeBSD ports collection. A number of Desktop environments such as GNOME, KDE and Xfce, embedded systems Although it explicitly focuses on the IA-32 and x86-64 platforms, FreeBSD also supports others such as ARM, PowerPC and MIPS to a lesser degree
21.
OpenBSD
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OpenBSD is a free and open source Unix-like computer operating system descended from Berkeley Software Distribution, a Research Unix derivative developed at the University of California, Berkeley. In late 1995, Theo de Raadt forked it from NetBSD, besides the operating system as a whole, the project maintains portable versions of many subsystems, most notably OpenSSH, which are available as packages in other operating systems. The project is known for its developers insistence on open-source code, good documentation, code correctness and it has strict policies on licensing, preferring the ISC license and other variants of the Simplified BSD License. Many of its security features are optional or absent in other operating systems and its developers frequently audit the source tree for software bugs and security holes. De Raadt coordinates the project from his home in Calgary, Alberta and its logo and mascot is a pufferfish named Puffy. In December 1994, NetBSD co-founder Theo de Raadt was asked to resign from his position as a developer and member of the NetBSD core team. The reason for this is not wholly clear, although there are claims that it was due to personality clashes within the NetBSD project, in October 1995, de Raadt founded OpenBSD, a new project forked from NetBSD1.0. The initial release, OpenBSD1.2, was made in July 1996, since then, the project has followed a schedule of a release every six months, each of which is supported for one year. Just how widely OpenBSD is used is hard to determine as its developers do not publish or collect usage statistics. OpenBSDs security enhancements, built-in cryptography, and the pf packet filter suit it for use in the security industry, such as on firewalls, intrusion-detection systems, and VPN gateways. Proprietary systems from several manufacturers are based on OpenBSD, including devices from Armorlogic, Calyptix Security, GeNUA, RTMX, later versions of Microsofts Services for UNIX, an extension to the Windows operating system providing Unix-like functionality, use large amounts of OpenBSD code. OpenBSD ships with the X Window System and is suitable for use on the desktop, packages are available for popular applications, including desktop environments such as GNOME, KDE, and Xfce, and web browsers such as Firefox and Chromium. The project also includes three window managers in the distribution, cwm, FVWM, and twm. OpenBSD used to include a fork of Apache 1.3, in the 5.6 release, Nginx was replaced with httpd, an HTTP server with FastCGI and Transport Layer Security support. As of May 2016, Apache and Nginx are still available as ports, development is continuous, and team management is open and tiered. Snapshot releases are available at frequent intervals. Maintenance patches for supported releases may be applied manually or by updating the system against the branch of the CVS repository for that release. The standard OpenBSD kernel, as maintained by the project, is recommended for end users
22.
AT&T
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AT&T Inc. is an American multinational telecommunications conglomerate, headquartered at Whitacre Tower in downtown Dallas, Texas. AT&T is the third-largest company in Texas, as of February 2017, AT&T is the 12th largest company in the world as measured by a composite of revenues, profits, assets and market valuation. AT&T is the largest telecommunications company in the world by revenue, as of 2017, it is also the 18th-largest mobile telecom operator in the world, with 135 million mobile customers. AT&T was ranked at #4 on the 2017 rankings of the worlds most valuable brands published by Brand Finance, Southwestern Bell changed its name to SBC Communications Inc. in 1995. In 2005, SBC purchased former parent AT&T Corp. and took on its branding, with the merged entity naming itself AT&T Inc. and using the iconic AT&T Corp. logo and stock-trading symbol. The current AT&T reconstitutes much of the former Bell System and includes ten of the original 22 Bell Operating Companies, AT&T can trace its origin back to the original Bell Telephone Company founded by Alexander Graham Bell after his invention of the telephone. This monopoly was known as the Bell System, and during this period, for periods of time, the former AT&T was the worlds largest phone company. In 1982, U. S. regulators broke up the AT&T monopoly, requiring AT&T to divest its regional subsidiaries and these new companies were known as Regional Bell Operating Companies, or more informally, Baby Bells. AT&T continued to long distance services, but as a result of this breakup, faced competition from new competitors such as MCI. Southwestern Bell was one of the created by the breakup of AT&T. The architect of divestiture for Southwestern Bell was Robert G. Pope, the company soon started a series of acquisitions. This includes the 1987 acquisition of Metromedia mobile business, and the acquisition of several companies in the early 1990s. In the later half of the 1990s, the company acquired several other companies, including some Baby Bells. During this time, the changed its name to SBC Communications. By 1998, the company was in the top 15 of the Fortune 500, in 2005, SBC purchased AT&T for $16 billion. After this purchase, SBC adopted the better-known AT&T name and brand, the current AT&T claims the original AT&Ts history as its own, though its corporate structure only dates from 1983. It also retains SBCs pre-2005 stock price history, in September 2013, AT&T announced it would expand into Latin America through a collaboration with Carlos Slims América Móvil. In December 2013, AT&T announced plans to sell its Connecticut wireline operations to Stamford-based Frontier Communications, in July 2015, AT&T purchased DirecTV for $48.5 billion, or $67.1 billion including assumed debt
23.
Workstation
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A workstation is a special computer designed for technical or scientific applications. Intended primarily to be used by one person at a time, they are connected to a local area network. Workstations offered higher performance than mainstream personal computers, especially with respect to CPU and graphics, memory capacity, and multitasking capability. Typically, the factor is that of a desktop computer, consist of a high resolution display, a keyboard and a mouse at a minimum. Workstations were the first segment of the market to present advanced accessories. The increasing capabilities of mainstream PCs in the late 1990s have blurred the lines somewhat with technical/scientific workstations, perhaps the first computer that might qualify as a workstation was the IBM1620, a small scientific computer designed to be used interactively by a single person sitting at the console. One peculiar feature of the machine was that it lacked any actual arithmetic circuitry, to perform addition, it required a memory-resident table of decimal addition rules. This saved on the cost of logic circuitry, enabling IBM to make it inexpensive, the machine was code-named CADET and rented initially for $1000 a month. In 1965, IBM introduced the IBM1130 scientific computer, which was meant as the successor to the 1620, both of these systems came with the ability to run programs written in Fortran and other languages. Both the 1620 and the 1130 were built into roughly desk-sized cabinets, both were available with add-on disk drives, printers, and both paper-tape and punched-card I/O. A console typewriter for direct interaction was standard on each, early examples of workstations were generally dedicated minicomputers, a system designed to support a number of users would instead be reserved exclusively for one person. A notable example was the PDP-8 from Digital Equipment Corporation, regarded to be the first commercial minicomputer, Lisp Machines were commercialized beginning 1980 by companies like Symbolics, Lisp Machines, Texas Instruments and Xerox. The first computer designed for single-users, with high-resolution graphics facilities was the Xerox Alto developed at Xerox PARC in 1973, other early workstations include the Terak 8510/a, Three Rivers PERQ and the later Xerox Star. Meanwhile, DARPAs VLSI Project created several spinoff graphics products as well, notably the SGI3130 and it was not uncommon to differentiate the target market for the products, with Sun and Apollo considered to be network workstations, while the SGI machines were graphics workstations. As RISC microprocessors became available in the mid-1980s, these were adopted by many workstation vendors, workstations tended to be very expensive, typically several times the cost of a standard PC and sometimes costing as much as a new car. However, minicomputers sometimes cost as much as a house, additionally, workstations, given their more specialized nature, tend to have higher profit margins than commodity-driven PCs. Additionally, the companies that make the products tend to have very good repair/replacement plans, some low-cost workstations are still expensive by PC standards, but offer binary compatibility with higher-end workstations and servers made by the same vendor. This allows software development to take place on low-cost desktop machines, Graphics workstations often shipped with graphics accelerators
24.
Digital Equipment Corporation
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Digital Equipment Corporation, also known as DEC and using the trademark Digital, was a major American company in the computer industry from the 1950s to the 1990s. DEC was a vendor of computer systems, including computers, software. Their PDP and successor VAX products were the most successful of all minicomputers in terms of sales, DEC was acquired in June 1998 by Compaq, in what was at that time the largest merger in the history of the computer industry. At the time, Compaq was focused on the market and had recently purchased several other large vendors. DEC was a major player overseas where Compaq had less presence, however, Compaq had little idea what to do with its acquisitions, and soon found itself in financial difficulty of its own. The company subsequently merged with Hewlett-Packard in May 2002, as of 2007 some of DECs product lines were still produced under the HP name. From 1957 until 1992, DECs headquarters were located in a wool mill in Maynard. DEC was acquired in June 1998 by Compaq, which merged with Hewlett-Packard in May 2002. Some parts of DEC, notably the business and the Hudson. Initially focusing on the end of the computer market allowed DEC to grow without its potential competitors making serious efforts to compete with them. Their PDP series of machines became popular in the 1960s, especially the PDP-8, looking to simplify and update their line, DEC replaced most of their smaller machines with the PDP-11 in 1970, eventually selling over 600,000 units and cementing DECs position in the industry. Originally designed as a follow-on to the PDP-11, DECs VAX-11 series was the first widely used 32-bit minicomputer and these systems were able to compete in many roles with larger mainframe computers, such as the IBM System/370. The VAX was a best-seller, with over 400,000 sold, at its peak, DEC was the second largest employer in Massachusetts, second only to the Massachusetts State Government. The rapid rise of the business microcomputer in the late 1980s, DECs last major attempt to find a space in the rapidly changing market was the DEC Alpha 64-bit RISC instruction set architecture. DEC initially started work on Alpha as a way to re-implement their VAX series, DEC was acquired in June 1998 by Compaq, in what was at that time the largest merger in the history of the computer industry. At the time, Compaq was focused on the market and had recently purchased several other large vendors. DEC was a major player overseas where Compaq had less presence, however, Compaq had little idea what to do with its acquisitions, and soon found itself in financial difficulty of its own. The company subsequently merged with Hewlett-Packard in May 2002, as of 2007 some of DECs product lines were still produced under the HP name
25.
Sun Microsystems
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Sun contributed significantly to the evolution of several key computing technologies, among them Unix, RISC processors, thin client computing, and virtualized computing. Sun was founded on February 24,1982, at its height, the Sun headquarters were in Santa Clara, California, on the former west campus of the Agnews Developmental Center. On January 27,2010, Oracle Corporation acquired Sun by for US$7.4 billion, other technologies include the Java platform, MySQL, and NFS. Sun was a proponent of open systems in general and Unix in particular, the initial design for what became Suns first Unix workstation, the Sun-1, was conceived by Andy Bechtolsheim when he was a graduate student at Stanford University in Palo Alto, California. Bechtolsheim originally designed the SUN workstation for the Stanford University Network communications project as a personal CAD workstation and it was designed around the Motorola 68000 processor with an advanced memory management unit to support the Unix operating system with virtual memory support. He built the first ones from spare parts obtained from Stanfords Department of Computer Science, on February 24,1982, Vinod Khosla, Andy Bechtolsheim, and Scott McNealy, all Stanford graduate students, founded Sun Microsystems. Bill Joy of Berkeley, a developer of the Berkeley Software Distribution. The Sun name is derived from the initials of the Stanford University Network, Sun was profitable from its first quarter in July 1982. By 1983 Sun was known for producing 68000-based systems with high-quality graphics that were the only computers other than DECs VAX to run 4. 2BSD and it licensed the computer design to other manufacturers, which typically used it to build Multibus-based systems running Unix from UniSoft. Suns initial public offering was in 1986 under the stock symbol SUNW, the symbol was changed in 2007 to JAVA, Sun stated that the brand awareness associated with its Java platform better represented the companys current strategy. Suns logo, which features four interleaved copies of the sun in the form of a rotationally symmetric ambigram, was designed by professor Vaughan Pratt. The initial version of the logo was orange and had the sides oriented horizontally and vertically, but it was rotated to stand on one corner and re-colored purple. In the dot-com bubble, Sun began making more money. It also began spending more, hiring workers and building itself out. Some of this was because of demand, but much was from web start-up companies anticipating business that would never happen. Sales in Suns important hardware division went into free-fall as customers closed shop, several quarters of steep losses led to executive departures, rounds of layoffs, and other cost cutting. In December 2001, the fell to the 1998, pre-bubble level of about $100. But it kept falling, faster than many other tech companies, a year later it had dipped below $10 but bounced back to $20
26.
SunOS
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SunOS is a Unix-branded operating system developed by Sun Microsystems for their workstation and server computer systems. SunOS1 only supported the Sun-2 series systems, including Sun-1 systems upgraded with Sun-2 CPU boards, SunOS2 supported Sun-2 and Sun-3 series systems. SunOS4 supported Sun-2, Sun-3, Sun386i and Sun-4 architectures, although SunOS4 was intended to be the first release to fully support Suns new SPARC processor, there was also a SunOS3.2 release with preliminary support for Sun-4 systems. SunOS4.1.2 introduced support for Suns first sun4m-architecture multiprocessor machines, since it had only a lock for the kernel. The last release of SunOS4 was 4.1.4 in 1994, the sun4, sun4c and sun4m architectures were supported in 4.1.4, sun4d was not supported. Sun continued to ship SunOS4.1.3 and 4.1.4 until December 27,1998, they were supported until September 30,2003. In 1987, AT&T Corporation and Sun announced that they were collaborating on a project to merge the most popular Unix flavors on the market at that time, BSD, System V and this would become System V Release 4. On September 4,1991, Sun announced that its next major OS release would switch from its BSD-derived source base to one based on SVR4, although the internal designation of this release would be SunOS5, from this point Sun began using the marketing name Solaris. The justification for this new overbrand was that it encompassed not only SunOS, even though the new SVR4-based OS was not expected to ship in volume until the following year, Sun immediately began using the new Solaris name to refer to the currently shipping SunOS4 release. Thus SunOS4.1.1 was rebranded Solaris 1.0, SunOS4.1. x micro versions continued to be released through 1994, and each of these was also given a Solaris 1. x equivalent name. In practice, these were still referred to by customers. Matching a SunOS5. x release to its corresponding Solaris marketing name is simple, for example, Solaris 2.4 incorporated SunOS5.4. There is one small twist, after Solaris 2.6, the 2. was dropped from the Solaris name, the latest Solaris release is named Solaris 11 and incorporates SunOS5.11. GUI environments bundled with earlier versions of SunOS included SunTools and NeWS, in 1989, Sun released OpenWindows, an OPEN LOOK-compliant X11-based environment which also supported SunView and NeWS applications. This became the default SunOS GUI in SunOS4.1.1, info on SunOS from OSdata Initial Solaris announcement
27.
UNIX System V
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UNIX System V is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983, four major versions of System V were released, numbered 1,2,3, and 4. It was the source of common commercial Unix features. System V is sometimes abbreviated to SysV, as of 2012, the Unix market is divided between three System V variants, IBMs AIX, Hewlett-Packards HP-UX and Oracles Solaris. System V was the successor to 1982s UNIX System III, while AT&T sold their own hardware that ran System V, most customers instead ran a version from a reseller, based on AT&Ts reference implementation. A standards document called the System V Interface Definition outlined the default features, in the 1980s and early-1990s, System V was considered one of the two major versions of UNIX, the other being the Berkeley Software Distribution. Historically, BSD was also commonly called BSD Unix or Berkeley Unix, the dispute had several levels, some technical and some cultural. The divide was roughly between longhairs and shorthairs, programmers and technical people tended to line up with Berkeley and BSD, more business-oriented types with AT&T and System V. While HP, IBM and others chose System V as the basis for their Unix offerings, other such as Sun Microsystems. Throughout its development, though, System V was infused with features from BSD, since the early 1990s, due to standardization efforts such as POSIX and the commercial success of Linux, the division between System V and BSD has become less important. System V, known inside Bell Labs as Unix 5.0, there was never an external release of Unix 4.0, which would have been System IV. This first release of System V was developed by AT&Ts UNIX Support Group, System V also included features such as the vi editor and curses from 4.1 BSD, developed at the University of California, Berkeley, it also improved performance by adding buffer and inode caches. It also added support for communication using messages, semaphores. SVR1 ran on DEC PDP-11 and VAX minicomputers, System V Release 2 was released in April,1984. It added shell functions and the SVID, new kernel features included record and file locking, demand paging, and copy on write. The concept of the base was formalized, and the DEC VAX-11/780 was chosen for this release. The porting base is the original version of a release. Educational source licenses for SVR2 were offered by AT&T for US$800 for the first CPU, a commercial source license was offered for $43,000, with three months of support, and a $16,000 price per additional CPU
28.
Tru64 UNIX
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Tru64 UNIX is a discontinued 64-bit UNIX operating system for the Alpha instruction set architecture, currently owned by Hewlett-Packard. Previously, Tru64 UNIX was a product of Compaq, and before that, Digital Equipment Corporation, as its original name suggests, Tru64 UNIX is based on the OSF/1 operating system. DECs previous UNIX product was known as Ultrix and was based on BSD and it is unusual among commercial UNIX implementations, as it is built on top of the Mach kernel developed at Carnegie Mellon University. Tru64 UNIX required the SRM boot firmware found on Alpha-based computer systems, in 1988, during the so-called Unix wars, DEC joined with IBM, Hewlett-Packard, and others to form the Open Software Foundation to develop a version of Unix. The fact that OSF/1 was one of the first operating systems to use the Mach kernel is cited as support of this assertion and it also incorporated a large part of the BSD kernel to provide UNIX API. Back at the time of its proliferation, OSF/1 was the third major flavor of UNIX together with System V and BSD. DECs original release of OSF/1 was in January 1992 for their line of MIPS-based DECstation workstations, DEC ported OSF/1 to their new Alpha AXP platform, and this was the first version of what is most commonly referred to as OSF/1. DEC OSF/1 AXP Release 1.2 was shipped on March 1993, OSF/1 AXP was a full 64-bit operating system and the native UNIX implementation for the Alpha architecture. From OSF/1 AXP V2.0 onwards, UNIX System V compatibility was also integrated into the system, HP also released a port of OSF/1 to the early HP 9000/700 workstations based on the PA-RISC1.1 architecture. This was withdrawn soon afterwards due to lack of software and hardware support compared to competing operating systems, apple Computer intended to base A/UX4.0 for their PowerPC-based Macintoshes on OSF/1, but the project was cancelled. IBM used OSF/1 as the basis of the AIX/ESA operating system for System/370, OSF/1 was also ported by Kendall Square Research to their proprietary processor architecture used in the KSR1 supercomputer. In 1994, after AT&T had sold UNIX System V to Novell and the rival Unix International consortium had disbanded, OSF/1 AD was a distributed version of OSF/1 developed for massively parallel supercomputers by Locus Computing Corporation. Variants of OSF/1 AD were used on such systems, including the Intel Paragon XP/S and ASCI Red, Convex Exemplar SPP-1200. In 1995, starting with release 3.2, DEC renamed OSF/1 AXP to Digital UNIX to reflect its conformance with the X/Open Single UNIX Specification. After Compaqs purchase of DEC in early 1998, with the release of version 4. 0F, Digital UNIX was renamed to Tru64 UNIX to emphasise its 64-bit-clean nature, in April 1999, Compaq announced that Tru64 UNIX5.0 successfully ran on Intels IA-64 simulator. However, this port was cancelled a few months later, a Chinese version of Tru64 UNIX named COSIX was jointly developed by Compaq and China National Computer Software & Technology Service Corporation. From release V5.0 Tru64 UNIX offered a facility named TruCluster Server. TruCluster utilised a cluster-wide filesystem visible to each member, plus member specific storage
29.
Open-source model
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Open-source software may be developed in a collaborative public manner. According to scientists who studied it, open-source software is a prominent example of open collaboration, a 2008 report by the Standish Group states that adoption of open-source software models has resulted in savings of about $60 billion per year to consumers. In the early days of computing, programmers and developers shared software in order to learn from each other, eventually the open source notion moved to the way side of commercialization of software in the years 1970-1980. In 1997, Eric Raymond published The Cathedral and the Bazaar and this source code subsequently became the basis behind SeaMonkey, Mozilla Firefox, Thunderbird and KompoZer. Netscapes act prompted Raymond and others to look into how to bring the Free Software Foundations free software ideas, the new term they chose was open source, which was soon adopted by Bruce Perens, publisher Tim OReilly, Linus Torvalds, and others. The Open Source Initiative was founded in February 1998 to encourage use of the new term, a Microsoft executive publicly stated in 2001 that open source is an intellectual property destroyer. I cant imagine something that could be worse than this for the software business, IBM, Oracle, Google and State Farm are just a few of the companies with a serious public stake in todays competitive open-source market. There has been a significant shift in the corporate philosophy concerning the development of FOSS, the free software movement was launched in 1983. In 1998, a group of individuals advocated that the free software should be replaced by open-source software as an expression which is less ambiguous. Software developers may want to publish their software with an open-source license, the Open Source Definition, notably, presents an open-source philosophy, and further defines the terms of usage, modification and redistribution of open-source software. Software licenses grant rights to users which would otherwise be reserved by law to the copyright holder. Several open-source software licenses have qualified within the boundaries of the Open Source Definition, the open source label came out of a strategy session held on April 7,1998 in Palo Alto in reaction to Netscapes January 1998 announcement of a source code release for Navigator. They used the opportunity before the release of Navigators source code to clarify a potential confusion caused by the ambiguity of the free in English. Many people claimed that the birth of the Internet, since 1969, started the open source movement, the Free Software Foundation, started in 1985, intended the word free to mean freedom to distribute and not freedom from cost. Since a great deal of free software already was free of charge, such software became associated with zero cost. The Open Source Initiative was formed in February 1998 by Eric Raymond and they sought to bring a higher profile to the practical benefits of freely available source code, and they wanted to bring major software businesses and other high-tech industries into open source. Perens attempted to open source as a service mark for the OSI. The Open Source Initiatives definition is recognized by governments internationally as the standard or de facto definition, OSI uses The Open Source Definition to determine whether it considers a software license open source
30.
NetBSD
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NetBSD is a free and open source Unix-like operating system that descends from Berkeley Software Distribution, a Research Unix derivative developed at the University of California, Berkeley. It was the second open-source BSD descendant formally released after it forked from the 386BSD branch of the BSD source-code repository. It continues to be developed and is available for many platforms, including large-scale server systems, desktop systems, and handheld devices. The NetBSD project focuses on code clarity, careful design, netBSDs source code is openly available and permissively licensed. The NetBSD project began as a result of frustration within the 386BSD developer community with the pace and they aimed to produce a unified, multi-platform, production-quality, BSD-based operating system. The name NetBSD was suggested by de Raadt, based on the importance and growth of such as the Internet at that time. The NetBSD source code repository was established on 21 March 1993 and this was derived from 386BSD0.1 plus the version 0.2.2 unofficial patchkit, with several programs from the Net/2 release missing from 386BSD re-integrated, and various other improvements. The first multi-platform release, NetBSD1.0, was made in October 1994, also in 1994, for disputed reasons, one of the founders, Theo de Raadt, was removed from the project. He later founded a new project, OpenBSD, from a version of NetBSD1.0 near the end of 1995. In 1998, NetBSD1.3 introduced the pkgsrc packages collection, until 2004, NetBSD1. x releases were made at roughly annual intervals, with minor patch releases in between. The previous minor releases are now divided into two categories, x. y stable maintenance releases and x. y. z releases containing only security, as the projects motto suggests, NetBSD has been ported to a large number of 32- and 64-bit architectures. These range from VAX minicomputers to Pocket PC PDAs, as of 2009, NetBSD supports 57 hardware platforms. The kernel and userland for these platforms are all built from a central unified source-code tree managed by CVS, currently, unlike other kernels such as μClinux, the NetBSD kernel requires the presence of an MMU in any given target architecture. NetBSDs portability is aided by the use of hardware abstraction layer interfaces for low-level hardware access such as bus input/output or DMA, using this portability layer, device drivers can be split into machine-independent and machine-dependent components. This makes a single driver easily usable on several platforms by hiding hardware access details, and reduces the work to port it to a new system. This permits a device driver for a PCI card to work without modifications, whether its in a PCI slot on an IA-32, Alpha, PowerPC, SPARC. Also, a driver for a specific device can operate via several different buses, like ISA, PCI. In comparison, Linux device driver code often must be reworked for each new architecture, as a consequence, in porting efforts by NetBSD and Linux developers, NetBSD has taken much less time to port to new hardware
31.
DragonFly BSD
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DragonFly BSD is a free and open source Unix-like operating system created as a fork of FreeBSD4.8. He sought to correct these problems within the FreeBSD project. Due to ongoing conflicts with other FreeBSD developers over the implementation of his ideas, despite this, the DragonFly BSD and FreeBSD projects still work together contributing bug fixes, driver updates, and other system improvements to each other. Intended to be the continuation of the FreeBSD4. Many concepts planned for DragonFly were inspired by the AmigaOS operating system, the messaging subsystem being developed is similar to those found in microkernels such as Mach, though it is less complex by design. Additionally, the migration of select kernel code into userspace has the benefit of making the more robust, if a userspace driver crashes. System calls are being split into userland and kernel versions and being encapsulated into messages, Linux and other Unix-like OS compatibility code is being migrated out similarly. As support for multiple instruction set architectures complicates symmetric multiprocessing support, DragonFly originally ran on the x86 architecture, however as of version 4.0 it is no longer supported. Since version 1.10, DragonFly supports 1,1 userland threading, inherited from FreeBSD, DragonFly also supports multi-threading. In DragonFly, each CPU has its own thread scheduler, inter-processor thread scheduling is also accomplished by sending asynchronous IPI messages. The LWKT subsystem is being employed to work among multiple kernel threads. In order to run safely on multiprocessor machines, access to shared resources must be serialized so that threads or processes do not attempt to modify the same resource at the same time. In order to prevent multiple threads from accessing or modifying a shared resource simultaneously, DragonFly employs critical sections, while both Linux and FreeBSD5 employ fine-grained mutex models to achieve higher performance on multiprocessor systems, DragonFly does not. Until recently, DragonFly also employed spls, but these were replaced with critical sections, critical sections are used to protect against local interrupts, individually for each CPU, guaranteeing that a thread currently being executed will not be preempted. Serializing tokens are used to prevent concurrent accesses from other CPUs and may be held simultaneously by multiple threads, blocked or sleeping threads therefore do not prevent other threads from accessing the shared resource unlike a thread that is holding a mutex. The serializing token code is evolving into something similar to the Read-copy-update feature now available in Linux. Unlike Linuxs current RCU implementation, DragonFlys is being implemented such that only processors competing for the same token are affected rather than all processors in the computer, DragonFly switched to multiprocessor safe slab allocator, which requires neither mutexes nor blocking operations for memory assignment tasks. It was eventually ported into standard C library in the userland, since release 1.8 DragonFly has a virtualization mechanism similar to User-mode Linux, allowing a user to run another kernel in the userland
32.
Darwin (operating system)
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Darwin is an open-source Unix operating system released by Apple Inc. in 2000. It is composed of code developed by Apple, as well as derived from NeXTSTEP, BSD, Mach. Darwin forms the set of components upon which macOS, iOS, watchOS. It is mostly POSIX-compatible, but has never, by itself, starting with Leopard, macOS has been certified as compatible with the Single UNIX Specification version 3. The heritage of Darwin began with NeXTs NeXTSTEP operating system, first released in 1989, after Apple bought NeXT in 1997, it announced it would base its next operating system on OPENSTEP. This was developed into Rhapsody in 1997, Mac OS X Server 1.0 in 1999, Mac OS X Public Beta in 2000, and Mac OS X10.0 in 2001. Up to Darwin 8.0.1, Apple released a binary installer after each major Mac OS X release that one to install Darwin on PowerPC. Minor updates were released as packages that were installed separately, Darwin is now only available as source code, except for the ARM variant, which has not been released in any form separately from iOS. However, the versions of Darwin are still available in binary form. The kernel of Darwin is XNU, a kernel that combines a heavily modified version of the Mach 3.0 kernel, various elements of BSD. The hybrid kernel design leverages the flexibility of a microkernel and the performance of a monolithic kernel. An open-source port of the XNU kernel exists that supports Darwin on Intel and AMD x86 platforms not officially supported by Apple, an open-source port of the XNU kernel also exists for ARM platforms. Older versions supported some or all of 32-bit PowerPC, 64-bit PowerPC and it supports the POSIX API by way of its BSD lineage and a large number of programs written for various other UNIX-like systems can be compiled on Darwin with no changes to the source code. Darwin does not include many of the elements of macOS, such as the Carbon and Cocoa APIs or the Quartz Compositor and Aqua user interface. The following is a table of major Darwin releases with their dates of release, note that the corresponding macOS release may have been released on a different date, refer to the macOS pages for those dates. In the build numbering system of macOS, every version has a unique beginning build number, Mac OS X v10.0 had build numbers starting with 4,10.1 had build numbers starting with 5, and so forth. The command uname -r in Terminal will show the Darwin version number, and the command uname -v will show the XNU build version string, due to the free software nature of Darwin, there are many projects that aim to modify or enhance the operating system. OpenDarwin was an operating system based on the Darwin system
33.
TrueOS
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TrueOS, is a Unix-like, desktop-oriented operating system built upon the most recent releases of FreeBSD-CURRENT. It aims to be easy to install by using an installation program. It provides official binary Nvidia and Intel drivers for hardware acceleration and an optional 3D desktop interface through KWin, TrueOS supports ZFS, and the installer offers disk encryption with geli so the system will require a passphrase before booting. TrueOS was founded by FreeBSD professional Kris Moore in early 2005 as PC-BSD, in August 2006 it was voted the most beginner friendly operating system by OSWeekly. com. The first beta of the PC-BSD consisted of only a GUI installer to get the user up and this was a major innovation for the time as anyone wishing to install FreeBSD would have to manually tweak and run through a text installer. PC-BSDs package manager took a different approach to installing software than many other Unix-like operating systems, up to and including version 8.2, by means of the pbiDIR website. Instead of using the FreeBSD Ports tree directly, PC-BSD used files with the. pbi filename extension which, an autobuild system tracked the FreeBSD ports collection and generated new. pbi files daily. All software packages and dependencies were installed from inside of the. pbi files in their own self-contained directories in /Programs, on October 10,2006, PC-BSD was acquired by enterprise-class hardware solution provider iXsystems. IXsystems now employs Kris Moore as a developer and leader of the project. In November 2007, iXsystems entered into an agreement with Frys Electronics whereby Frys Electronics stores nationwide carry boxed copies of PC-BSD version 1.4. In January 2008, iXsystems entered into an agreement with Micro Center. On September 1,2016, the PC-BSD team announced that the name of the system will change to TrueOS. Along with the rebranding, the project became a rolling release distribution. On November 15,2016, TrueOS began the transition from FreeBSDs rc. d to OpenRC as the default init system, apart from Gentoo/Alt, where OpenRC was initially developed, this is the only other major BSD based operating system using OpenRC. Since version 7, PC-BSD began following the numbering system as FreeBSD. Since version 9.0, the KDE SC, customized to support tighter application integration, was no longer the only desktop environment supported by PC-BSD. Starting with version 9.0, PC-BSD added other desktop environments, including GNOME, Xfce, LXDE, PC-BSD used to support both x86 and x86-64 architectures. Support for x86 was dropped in version 9.2, starting in September 2016 with the rebranding of PC-BSD, TrueOS became a rolling release distribution based on FreeBSDs current branch
34.
Microsoft Windows
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Microsoft Windows is a metafamily of graphical operating systems developed, marketed, and sold by Microsoft. It consists of families of operating systems, each of which cater to a certain sector of the computing industry with the OS typically associated with IBM PC compatible architecture. Active Windows families include Windows NT, Windows Embedded and Windows Phone, defunct Windows families include Windows 9x, Windows 10 Mobile is an active product, unrelated to the defunct family Windows Mobile. Microsoft introduced an operating environment named Windows on November 20,1985, Microsoft Windows came to dominate the worlds personal computer market with over 90% market share, overtaking Mac OS, which had been introduced in 1984. Apple came to see Windows as an encroachment on their innovation in GUI development as implemented on products such as the Lisa. On PCs, Windows is still the most popular operating system, however, in 2014, Microsoft admitted losing the majority of the overall operating system market to Android, because of the massive growth in sales of Android smartphones. In 2014, the number of Windows devices sold was less than 25% that of Android devices sold and this comparison however may not be fully relevant, as the two operating systems traditionally target different platforms. As of September 2016, the most recent version of Windows for PCs, tablets, smartphones, the most recent versions for server computers is Windows Server 2016. A specialized version of Windows runs on the Xbox One game console, Microsoft, the developer of Windows, has registered several trademarks each of which denote a family of Windows operating systems that target a specific sector of the computing industry. It now consists of three operating system subfamilies that are released almost at the time and share the same kernel. Windows, The operating system for personal computers, tablets. The latest version is Windows 10, the main competitor of this family is macOS by Apple Inc. for personal computers and Android for mobile devices. Windows Server, The operating system for server computers, the latest version is Windows Server 2016. Unlike its clients sibling, it has adopted a strong naming scheme, the main competitor of this family is Linux. Windows PE, A lightweight version of its Windows sibling meant to operate as an operating system, used for installing Windows on bare-metal computers. The latest version is Windows PE10.0.10586.0, Windows Embedded, Initially, Microsoft developed Windows CE as a general-purpose operating system for every device that was too resource-limited to be called a full-fledged computer. The following Windows families are no longer being developed, Windows 9x, Microsoft now caters to the consumers market with Windows NT. Windows Mobile, The predecessor to Windows Phone, it was a mobile operating system
35.
Apple Inc.
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Apple is an American multinational technology company headquartered in Cupertino, California that designs, develops, and sells consumer electronics, computer software, and online services. Apples consumer software includes the macOS and iOS operating systems, the media player, the Safari web browser. Its online services include the iTunes Store, the iOS App Store and Mac App Store, Apple Music, Apple was founded by Steve Jobs, Steve Wozniak, and Ronald Wayne in April 1976 to develop and sell personal computers. It was incorporated as Apple Computer, Inc. in January 1977, Apple joined the Dow Jones Industrial Average in March 2015. In November 2014, Apple became the first U. S. company to be valued at over US$700 billion in addition to being the largest publicly traded corporation in the world by market capitalization. The company employs 115,000 full-time employees as of July 2015 and it operates the online Apple Store and iTunes Store, the latter of which is the worlds largest music retailer. Consumers use more than one billion Apple products worldwide as of March 2016, Apples worldwide annual revenue totaled $233 billion for the fiscal year ending in September 2015. This revenue accounts for approximately 1. 25% of the total United States GDP.1 billion, the corporation receives significant criticism regarding the labor practices of its contractors and its environmental and business practices, including the origins of source materials. Apple was founded on April 1,1976, by Steve Jobs, Steve Wozniak, the Apple I kits were computers single-handedly designed and hand-built by Wozniak and first shown to the public at the Homebrew Computer Club. The Apple I was sold as a motherboard, which was less than what is now considered a personal computer. The Apple I went on sale in July 1976 and was market-priced at $666.66, Apple was incorporated January 3,1977, without Wayne, who sold his share of the company back to Jobs and Wozniak for $800. Multimillionaire Mike Markkula provided essential business expertise and funding of $250,000 during the incorporation of Apple, during the first five years of operations revenues grew exponentially, doubling about every four months. Between September 1977 and September 1980 yearly sales grew from $775,000 to $118m, the Apple II, also invented by Wozniak, was introduced on April 16,1977, at the first West Coast Computer Faire. It differed from its rivals, the TRS-80 and Commodore PET, because of its character cell-based color graphics. While early Apple II models used ordinary cassette tapes as storage devices, they were superseded by the introduction of a 5 1/4 inch floppy disk drive and interface called the Disk II. The Apple II was chosen to be the platform for the first killer app of the business world, VisiCalc. VisiCalc created a market for the Apple II and gave home users an additional reason to buy an Apple II. Before VisiCalc, Apple had been a distant third place competitor to Commodore, by the end of the 1970s, Apple had a staff of computer designers and a production line
36.
MacOS
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Within the market of desktop, laptop and home computers, and by web usage, it is the second most widely used desktop OS after Microsoft Windows. Launched in 2001 as Mac OS X, the series is the latest in the family of Macintosh operating systems, Mac OS X succeeded classic Mac OS, which was introduced in 1984, and the final release of which was Mac OS9 in 1999. An initial, early version of the system, Mac OS X Server 1.0, was released in 1999, the first desktop version, Mac OS X10.0, followed in March 2001. In 2012, Apple rebranded Mac OS X to OS X. Releases were code named after big cats from the release up until OS X10.8 Mountain Lion. Beginning in 2013 with OS X10.9 Mavericks, releases have been named after landmarks in California, in 2016, Apple rebranded OS X to macOS, adopting the nomenclature that it uses for their other operating systems, iOS, watchOS, and tvOS. The latest version of macOS is macOS10.12 Sierra, macOS is based on technologies developed at NeXT between 1985 and 1997, when Apple acquired the company. The X in Mac OS X and OS X is pronounced ten, macOS shares its Unix-based core, named Darwin, and many of its frameworks with iOS, tvOS and watchOS. A heavily modified version of Mac OS X10.4 Tiger was used for the first-generation Apple TV, Apple also used to have a separate line of releases of Mac OS X designed for servers. Beginning with Mac OS X10.7 Lion, the functions were made available as a separate package on the Mac App Store. Releases of Mac OS X from 1999 to 2005 can run only on the PowerPC-based Macs from the time period, Mac OS X10.5 Leopard was released as a Universal binary, meaning the installer disc supported both Intel and PowerPC processors. In 2009, Apple released Mac OS X10.6 Snow Leopard, in 2011, Apple released Mac OS X10.7 Lion, which no longer supported 32-bit Intel processors and also did not include Rosetta. All versions of the system released since then run exclusively on 64-bit Intel CPUs, the heritage of what would become macOS had originated at NeXT, a company founded by Steve Jobs following his departure from Apple in 1985. There, the Unix-like NeXTSTEP operating system was developed, and then launched in 1989 and its graphical user interface was built on top of an object-oriented GUI toolkit using the Objective-C programming language. This led Apple to purchase NeXT in 1996, allowing NeXTSTEP, then called OPENSTEP, previous Macintosh operating systems were named using Arabic numerals, e. g. Mac OS8 and Mac OS9. The letter X in Mac OS Xs name refers to the number 10 and it is therefore correctly pronounced ten /ˈtɛn/ in this context. However, a common mispronunciation is X /ˈɛks/, consumer releases of Mac OS X included more backward compatibility. Mac OS applications could be rewritten to run natively via the Carbon API, the consumer version of Mac OS X was launched in 2001 with Mac OS X10.0. Reviews were variable, with praise for its sophisticated, glossy Aqua interface
37.
IOS
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IOS is a mobile operating system created and developed by Apple Inc. exclusively for its hardware. It is the system that presently powers many of the companys mobile devices, including the iPhone, iPad. It is the second most popular operating system globally after Android. IPad tablets are also the second most popular, by sales, originally unveiled in 2007 for the iPhone, iOS has been extended to support other Apple devices such as the iPod Touch and the iPad. As of January 2017, Apples App Store contains more than 2.2 million iOS applications,1 million of which are native for iPads and these mobile apps have collectively been downloaded more than 130 billion times. The iOS user interface is based upon direct manipulation, using multi-touch gestures, interface control elements consist of sliders, switches, and buttons. Internal accelerometers are used by applications to respond to shaking the device or rotating it in three dimensions. Apple has been praised for incorporating thorough accessibility functions into iOS, enabling users with vision. Major versions of iOS are released annually, the current version, iOS10, was released on September 13,2016. In iOS, there are four layers, the Core OS, Core Services, Media. In 2005, when Steve Jobs began planning the iPhone, he had a choice to either shrink the Mac, forstall was also responsible for creating a software development kit for programmers to build iPhone apps, as well as an App Store within iTunes. The operating system was unveiled with the iPhone at the Macworld Conference & Expo on January 9,2007, and released in June of that year. At the time of its unveiling in January, Steve Jobs claimed, iPhone runs OS X and runs applications, but at the time of the iPhones release. Initially, third-party native applications were not supported, Steve Jobs reasoning was that developers could build web applications through the Safari web browser that would behave like native apps on the iPhone. In October 2007, Apple announced that a native Software Development Kit was under development, on March 6,2008, Apple held a press event, announcing the iPhone SDK. The iOS App Store was opened on July 10,2008 with an initial 500 applications available.2 million in January 2017, as of March 2016,1 million apps are natively compatible with the iPad tablet computer. These apps have collectively been downloaded more than 130 billion times, App intelligence firm Sensor Tower has estimated that the App Store will reach 5 million apps by the year 2020. On September 5,2007, Apple released the iPod Touch, Apple also sold more than one million iPhones during the 2007 holiday season
38.
Junos OS
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Junos OS is the FreeBSD-based operating system used in Juniper Networks hardware routers. It is a system that is used in Junipers routing, switching. Juniper offers a Software Development Kit to partners and customers to allow additional customization, the biggest competitor of Junos is Cisco Systems IOS. Junos provides a code base across most of Junipers platforms. Juniper has issued a new release of Junos every 90 days since 1998, Junos supports a variety of routing protocols. With the introduction of the SRX and J-series platforms, it also supports flow mode, which includes stateful firewalling, NAT and its a flexible routing policy language that is used for controlling route advertisements and path selection. Junos generally adheres to standards for routing and MPLS. The operating system supports high availability mechanisms that are not standard to Unix, Junos operating system is primarily based on FreeBSD. Because FreeBSD is a Unix implementation, customers can access a Unix shell, Junos runs on most or all Juniper hardware systems. After Juniper acquired NetScreen, it integrated ScreenOS security functions into its own Junos network operating system, the Junos CLI is a text-based command interface for configuring, troubleshooting, and monitoring the Juniper device and network traffic associated with it. It supports two types of command modes, the Configuration mode is used for configuring the Juniper router, switch, or security device, by adding, deleting, or modifying statements in the configuration hierarchy. It provides a set of tools and application programming interfaces, including interfaces to Junos routing, firewall filter, UI, Juniper Networks also employs the Junos SDK internally to develop parts of Junos and many Junos applications such as OpenFlow for Junos, and other traffic services. Official website Juniper Networks to Use Oracle Berkeley DB in JUNOS Software
39.
PlayStation 3 system software
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The PlayStation®3 system software is the updatable firmware and operating system of the PlayStation 3. The process of updating is almost identical to that of the PlayStation Portable, PlayStation Vita, the initial slim PS3s SKU shipped with a unique firmware with new features, also seen in software 3.00. The native operating system of the PlayStation 3 is CellOS, which is believed to be a fork of FreeBSDPlayStation License, tCP/IP stack fingerprinting identifies a PlayStation 3 as running FreeBSD, and the PlayStation 3 is known to contain code from FreeBSD and NetBSD. The 3D computer graphics API software used in the PlayStation 3 is LibGCM and PSGL, based on OpenGL ES, LibGCM is a low level API, and PSGL is a higher level API, but most developers preferred to use libGCM due to higher levels of performance. This is similar to the later PlayStation 4 console which also has two APIs, the low level GNM and the higher level GNMX. Due to the fact that it requires an agreement with Sony. XMB displays icons horizontally across the screen that be seen as categories, when one category is selected, there are usually more specific options then available to select that are spread vertically above and below the selected icon. Users may navigate among these options by using the up and down buttons of the D-pad, the basic features offered by XMB implementations varies based on device and software version. Apart from those appearing in the PSP console such as icons for Photos, Music and Games. Also, XMB offers a degree of multitasking, in-game XMB features were added to the PS3 properly with firmware version 2.41 after causing early implementation problems. The PlayStation 3 supports Remote Play with Sonys handheld game consoles, the PlayStation Portable, however, unlike Remote Play between the PlayStation 4 and the PlayStation Vita, the problem with PS3 was that it only supported a select few titles and results were often laggy. However, it is clear that Remote Play with the PS3 was the bed for its much better integration with the PS4. Furthermore, they can use a service called Cross-Buy which allows them to buy certain games that support this one time. Not only that, but in the case of most such games, their saved games actually transfer back, there is also a feature called Cross-Play covering any PlayStation Vita software title that can interact with a PlayStation 3 software title. Different software titles use Cross-Play in different ways, for example, Ultimate Marvel vs. Capcom 3 is a title supporting the Cross-Play feature, and the PS3 version of the game can be controlled using the PS Vita system. In addition, some PS3 games can be played on the PS Vita using the PlayStation Now streaming service, similar to many other consoles, the PlayStation 3 is capable of photo, audio, and video playback in a variety of formats. It also includes various photo slideshow options and several music visualizations, furthermore, the PlayStation 3 is able to play Blu-ray and DVD movies as well as CDs out of the box, and also capable of adopting streaming media services such as Netflix. However, unlike the PS4, the PS3 is able to play Adobe Flash, early versions of the PlayStation 3 system software also provided a feature called OtherOS that was available on the PS3 systems prior to the slimmer models launched in September 2009
40.
Research Unix
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The term Research Unix first appeared in the Bell System Technical Journal to distinguish it from other versions internal to Bell Labs whose code-base had diverged from the primary CSRC version. However, that term was little-used until Version 8 Unix, but has been applied to earlier versions as well. Prior to V8, the system was most commonly called simply UNIX or the UNIX Time-Sharing System. AT&T licensed Version 5 to educational institutions, and Version 6 also to commercial sites, schools paid $200 and others $20,000, discouraging most commercial use, but Version 6 was the most widely used version into the 1980s. So, the first Research Unix would be the First Edition, another common way of referring to them is Version x Unix, where x is the manual edition. All modern editions of Unix—excepting Unix-like implementations such as Coherent, Minix, starting with the 8th Edition, versions of Research Unix had a close relationship to BSD. This began by using 4. 1cBSD as the basis for the 8th Edition. 1c and this continued with 9th and 10th. The ordinary user command-set was, I guess, a bit more BSD-flavored than SysVish, Version 3, Version 4 and Version 5 should not be confused with the UNIX3.0, UNIX4.0 and UNIX5.0 releases by the AT&T UNIX Support Group. After Version 10, Unix development at Bell Labs was stopped in favor of a system, Plan 9 from Bell Labs. In 2002, Caldera International released V7 Unix as FOSS under a permissive BSD-like software license, in 2017, Unix Heritage Society and Alcatel-Lucent USA Inc. List of new features in Research Unix 9th Edition
41.
Bell Labs
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Nokia Bell Labs is an American research and scientific development company, owned by Finnish company Nokia. Its headquarters are located in Murray Hill, New Jersey, in addition to laboratories around the rest of the United States. The historic laboratory originated in the late 19th century as the Volta Laboratory, Bell Labs was also at one time a division of the American Telephone & Telegraph Company, half-owned through its Western Electric manufacturing subsidiary. Eight Nobel Prizes have been awarded for work completed at Bell Laboratories, in 1880, the French government awarded Alexander Graham Bell the Volta Prize of 50,000 francs, approximately US$10,000 at that time for the invention of the telephone. Bell used the award to fund the Volta Laboratory in Washington, D. C. in collaboration with Sumner Tainter, the laboratory is also variously known as the Volta Bureau, the Bell Carriage House, the Bell Laboratory and the Volta Laboratory. The laboratory focused on the analysis, recording, and transmission of sound, Bell used his considerable profits from the laboratory for further research and education to permit the diffusion of knowledge relating to the deaf. This resulted in the founding of the Volta Bureau c,1887, located at Bells fathers house at 1527 35th Street in Washington, D. C. where its carriage house became their headquarters in 1889. In 1893, Bell constructed a new building, close by at 1537 35th St. specifically to house the lab, the building was declared a National Historic Landmark in 1972. In 1884, the American Bell Telephone Company created the Mechanical Department from the Electrical, the first president of research was Frank B. Jewett, who stayed there until 1940, ownership of Bell Laboratories was evenly split between AT&T and the Western Electric Company. Its principal work was to plan, design, and support the equipment that Western Electric built for Bell System operating companies and this included everything from telephones, telephone exchange switches, and transmission equipment. Bell Labs also carried out consulting work for the Bell Telephone Company, a few workers were assigned to basic research, and this attracted much attention, especially since they produced several Nobel Prize winners. Until the 1940s, the principal locations were in and around the Bell Labs Building in New York City. Of these, Murray Hill and Crawford Hill remain in existence, the largest grouping of people in the company was in Illinois, at Naperville-Lisle, in the Chicago area, which had the largest concentration of employees prior to 2001. Since 2001, many of the locations have been scaled down or closed. The Holmdel site, a 1.9 million square foot structure set on 473 acres, was closed in 2007, the mirrored-glass building was designed by Eero Saarinen. In August 2013, Somerset Development bought the building, intending to redevelop it into a commercial and residential project. The prospects of success are clouded by the difficulty of readapting Saarinens design and by the current glut of aging, eight Nobel Prizes have been awarded for work completed at Bell Laboratories
. doi:10.1145/6041.6043.
