1.
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
2.
NeXT
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NeXT was founded by Jobs after he was ousted at Apple, along with several co-workers. NeXT introduced the first NeXT Computer in 1988, and the smaller NeXTstation in 1990, the NeXT computers experienced relatively limited sales, with estimates of about 50,000 units shipped in total. Nevertheless, their innovative object-oriented NeXTSTEP operating system and development environment were highly influential, NeXT later released much of the NeXTSTEP system as a programming environment standard called OpenStep. NeXT withdrew from the business in 1993 to concentrate on marketing OPENSTEP for Mach, its own OpenStep implementation. NeXT also developed WebObjects, one of the first enterprise Web application frameworks, Apple purchased NeXT in 1997 for $429 million, and 1.5 million shares of Apple stock. As part of the agreement, Steve Jobs, Chairman and CEO of NeXT Software, returned to Apple, the founder promised to merge software from NeXT with Apples hardware platforms, eventually resulting in macOS, iOS, watchOS and tvOS. Parts of these systems incorporated the OPENSTEP foundation. In 1985, Apple co-founder Steve Jobs led Apples SuperMicro division, the Macintosh had been successful on university campuses partly because of the Apple University Consortium, which allowed students and institutions to buy the computers at a discount. The consortium had earned more than $50 million on computers by February 1984, while chairman, Jobs visited university departments and faculty members to sell Macintosh. Jobs met Paul Berg, a Nobel Laureate in chemistry, at a luncheon held in Silicon Valley to honor François Mitterrand, wet labs were prohibitively expensive for lower-level courses and were too complex to be simulated on personal computers of the time. Jobs was intrigued by Bergs concept of a workstation and contemplated starting a higher education company in the fall of 1985. Jobs division did not release upgraded versions of the Macintosh and most of the Macintosh Office, as a result, sales plummeted, and Apple was forced to write off millions of dollars in unsold inventory. Apples chief executive officer John Sculley ousted Jobs from his role at Apple. Later that year, Jobs began a struggle to regain control of the company. The board of directors sided with Sculley while Jobs took a visit to Western Europe. After several months of being sidelined, Jobs resigned from Apple on September 13,1985 and he told the board he was leaving to set up a new computer company, and that he would be taking several Apple employees from the SuperMicro division with him. He also told the board that his new company would not compete with Apple, Jobs named his new company Next, Inc. A number of former Apple employees followed him to Next, including Joanna Hoffman, Bud Tribble, George Crow, Rich Page, Susan Barnes, Susan Kare, and Danl Lewin
3.
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
4.
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
5.
Solaris (operating system)
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Solaris is a Unix operating system originally developed by Sun Microsystems. It superseded their earlier SunOS in 1993, Oracle Solaris, so named as of 2010, has been owned by Oracle Corporation since the Sun acquisition by Oracle in January 2010. Solaris is known for its scalability, especially on SPARC systems, Solaris supports SPARC-based and x86-based workstations and servers from Oracle and other vendors, with efforts underway to port to additional platforms. Solaris is registered as compliant with the Single Unix Specification, historically, Solaris was developed as proprietary software. In June 2005, Sun Microsystems released most of the codebase under the CDDL license, with OpenSolaris, Sun wanted to build a developer and user community around the software. After the acquisition of Sun Microsystems in January 2010, Oracle decided to discontinue the OpenSolaris distribution, in August 2010, Oracle discontinued providing public updates to the source code of the Solaris kernel, effectively turning Solaris 11 back into a closed source proprietary operating system. Following that, in 2011 the Solaris 11 kernel source code leaked to BitTorrent, however, through the Oracle Technology Network, industry partners can still gain access to the in-development Solaris source code. Source code for the source components of Solaris 11 is available for download from Oracle. In 1987, AT&T Corporation and Sun announced that they were collaborating on a project to merge the most popular Unix variants on the market at that time, BSD, System V and this became Unix System V Release 4. On September 4,1991, Sun announced that it would replace its existing BSD-derived Unix, SunOS4 and this was identified internally as SunOS5, but a new marketing name was introduced at the same time, Solaris 2. The justification for this new overbrand was that it encompassed not only SunOS, but also the OpenWindows graphical user interface and Open Network Computing functionality. Although SunOS4.1. x micro releases were retroactively named Solaris 1 by Sun, for releases based on SunOS5, the SunOS minor version is included in the Solaris release number. For example, Solaris 2.4 incorporates SunOS5.4. After Solaris 2.6, the 2. was dropped from the name, so Solaris 7 incorporates SunOS5.7. Although SunSoft stated in its initial Solaris 2 press release their intent to support both SPARC and x86 systems, the first two Solaris 2 releases,2.0 and 2.1, were SPARC-only. An x86 version of Solaris 2.1 was released in June 1993, about 6 months after the SPARC version, as a desktop and it included the Wabi emulator to support Windows applications. At the time, Sun also offered the Interactive Unix system that it had acquired from Interactive Systems Corporation, in 1994, Sun released Solaris 2.4, supporting both SPARC and x86 systems from a unified source code base. Solaris uses a code base for the platforms it supports, SPARC
6.
Windows NT
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Windows NT is a family of operating systems produced by Microsoft, the first version of which was released in July 1993. It is a processor-independent, multiprocessing, multi-user operating system, the first version of Windows NT was Windows NT3.1 and was produced for workstations and server computers. It was intended to complement consumer versions of Windows that were based on MS-DOS, gradually, the Windows NT family was expanded into Microsofts general-purpose operating system product line for all personal computers, deprecating the Windows 9x family. NT was formerly expanded to New Technology but no longer carries any specific meaning, starting with Windows 2000, NT was removed from the product name and is only included in the product version string. NT was the first purely 32-bit version of Windows, whereas its consumer-oriented counterparts, Windows 3. 1x and it is a multi-architecture operating system. Initially, it supported several CPU architectures, including IA-32, MIPS, DEC Alpha, PowerPC, the latest versions support x86 and ARM. This lineage is made clear in Cutlers foreword to Inside Windows NT by Helen Custer and it has been suggested that Dave Cutler intended the initialism WNT as a play on VMS, incrementing each letter by one. However, the project was intended as a follow-on to OS/2 and was referred to as NT OS/2 before receiving the Windows brand. One of the original NT developers, Mark Lucovsky, states that the name was taken from the original target processor—the Intel i860, the letters were dropped from the names of releases from Windows 2000 onwards, though Microsoft described that product as being Built on NT Technology. A main design goal of NT was hardware and software portability, the idea was to have a common code base with a custom Hardware Abstraction Layer for each platform. However, support for MIPS, Alpha, and PowerPC was later dropped in Windows 2000, broad software compatibility was achieved with support for several API personalities, including Windows API, POSIX, and OS/2 APIs – the latter two were phased out starting with Windows XP. Partial MS-DOS compatibility was achieved via an integrated DOS Virtual Machine – although this feature is being phased out in the x86-64 architecture, NT supported per-object access control lists allowing a rich set of security permissions to be applied to systems and services. NT supported Windows network protocols, inheriting the previous OS/2 LAN Manager networking, Windows NT3.1 was the first version of Windows to use 32-bit flat virtual memory addressing on 32-bit processors. Its companion product, Windows 3.1, used segmented addressing, notably, in Windows NT3. x, several I/O driver subsystems, such as video and printing, were user-mode subsystems. In Windows NT4, the video, server, and printer spooler subsystems were moved into kernel mode, NTFS, a journaled, secure file system, was created for NT. Windows NT also allows for other file systems, starting with versions 3.1. Windows NT introduced its own model, the Windows NT driver model. With Windows 2000, the Windows NT driver model was enhanced to become the Windows Driver Model, which was first introduced with Windows 98, but was based on the NT driver model
7.
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
8.
Mach (kernel)
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Mach is a kernel developed at Carnegie Mellon University to support operating system research, primarily distributed and parallel computing. Mach is often mentioned as one of the earliest examples of a microkernel, however, not all versions of Mach are microkernels. Machs derivatives are the basis of the operating system kernels in GNU Hurd. The project at Carnegie Mellon ran from 1985 to 1994, ending with Mach 3.0, Mach was developed as a replacement for the kernel in the BSD version of Unix, so no new operating system would have to be designed around it. Experimental research on Mach appears to have ended, although Mach and these include NeXTSTEP and OpenStep, upon which macOS is based—all using the XNU operating system kernel which incorporates an earlier, non-microkernel, Mach as a major component. The Mach virtual memory management system was adopted in 4. 4BSD by the BSD developers at CSRG. Mach is the successor to Carnegie Mellons Accent kernel. The lead developer on the Mach project, Richard Rashid, has been working at Microsoft since 1991 in various top-level positions revolving around the Microsoft Research division. Another of the original Mach developers, Avie Tevanian, was head of software at NeXT. Rashid liked Giuses spelling Mach so much that it prevailed, a key concept in the original Unix operating system was the idea of a pipe. A pipe was an abstraction that allowed data to be moved from program to program using the command line, using pipes, users could link together multiple programs to complete tasks, feeding data through several small programs in turn. Pipes were built on the underlying input/output system and this system was, in turn, based on a model where drivers were expected to periodically block while they waited for tasks to complete. For instance, a driver might send a line of text to a line printer. In this case, the driver would indicate that it was blocked, in the pipes system the limited resource was memory, and when one program filled the memory assigned to the pipe, it would naturally block. Normally this would cause the program to run, emptying the pipe out again. However, the implementation of pipes as memory buffers meant data was being copied from program to program and this made the pipe concept unsuitable for tasks where quick turnaround or low latency was needed, as is the case in most device drivers. The operating system kernel and most core functionality was instead written as a large program. As the operating system added new functionality, the size and complexity of the kernel grew, Unix pipes offered a conceptual system that could be used to build arbitrarily complex solutions out of small interacting programs
9.
Computing platform
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Computing platform means in general sense, where any piece of software is executed. It may be the hardware or the system, even a web browser or other application. The term computing platform can refer to different abstraction levels, including a hardware architecture, an operating system. In total it can be said to be the stage on which programs can run. For example, an OS may be a platform that abstracts the underlying differences in hardware, platforms may also include, Hardware alone, in the case of small embedded systems. Embedded systems can access hardware directly, without an OS, this is referred to as running on bare metal, a browser in the case of web-based software. The browser itself runs on a platform, but this is not relevant to software running within the browser. An application, such as a spreadsheet or word processor, which hosts software written in a scripting language. This can be extended to writing fully-fledged applications with the Microsoft Office suite as a platform, software frameworks that provide ready-made functionality. Cloud computing and Platform as a Service, the social networking sites Twitter and facebook are also considered development platforms. A virtual machine such as the Java virtual machine, applications are compiled into a format similar to machine code, known as bytecode, which is then executed by the VM. A virtualized version of a system, including virtualized hardware, OS, software. These allow, for instance, a typical Windows program to run on what is physically a Mac, some architectures have multiple layers, with each layer acting as a platform to the one above it. In general, a component only has to be adapted to the layer immediately beneath it, however, the JVM, the layer beneath the application, does have to be built separately for each OS
10.
PA-RISC
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PA-RISC is an instruction set architecture developed by Hewlett-Packard. As the name implies, it is an instruction set computer architecture. The design is referred to as HP/PA for Hewlett Packard Precision Architecture. The architecture was introduced on 26 February 1986, when the HP3000 Series 930 and HP9000 Model 840 computers were launched featuring the first implementation, PA-RISC has been succeeded by the Itanium ISA, jointly developed by HP and Intel. HP stopped selling PA-RISC-based HP9000 systems at the end of 2008, in the late 1980s, HP was building four series of computers, all based on CISC CPUs. One line was the IBM PC compatible Intel i286-based Vectra Series, HP planned to use PA-RISC to move all of their non-PC compatible machines to a single RISC CPU family. Precision Architecture was introduced in 1986 and it had thirty-two 32-bit integer registers and sixteen 64-bit floating-point registers. The number of floating-point registers was doubled in the 1.1 version to 32 once it became apparent that 16 were inadequate, the architects included Allen Baum, Hans Jeans, Michael J. Mahon, Ruby Bei-Loh Lee, Russel Kao, Steve Muchnick, Terrence C. Miller, David Fotland, and William S. Worley, the first implementation was the TS1, a central processing unit built from discrete transistor-transistor logic devices. Later implementations were multi-chip VLSI designs fabricated in NMOS processes and CMOS. They were first used in a new series of HP3000 machines in the late 1980s – the 930 and 950, commonly known at the time as Spectrum systems, the HP9000 machines were soon upgraded with the PA-RISC processor as well, running the HP-UX version of UNIX. Other operating systems ported to the PA-RISC architecture include Linux, OpenBSD, NetBSD, an interesting aspect of the PA-RISC line is that most of its generations have no Level 2 cache. Instead large Level 1 caches are used, formerly as separate chips connected by a bus, only the PA-7100LC and PA-7300LC had L2 caches. Another innovation of the PA-RISC was the addition of vectorized instructions in the form of MAX, Precision RISC Organization, an industry group led by HP, was founded in 1992, to promote the PA-RISC architecture. Members included Hitachi, Redbrick Software, Allegro Consultants, Mitsubishi, NEC, OKI, the ISA was extended in 1996 to 64 bits, with this revision named PA-RISC2.0. The first PA-RISC2.0 implementation was the PA-8000, which was introduced in January 1996. net Comprehensive PA-RISC chip and computer information chipdb. org Images of different PA-RISC processors
11.
SPARC
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The Scalable Processor Architecture is a reduced instruction set computing instruction set architecture originally developed by Sun Microsystems. Since the establishment of SPARC International, Inc. in 1989, SPARC International is also responsible for licensing and promoting the SPARC architecture, managing SPARC trademarks, and providing conformance testing. As a result of SPARC International, SPARC is fully open, non-proprietary, later, SPARC processors were used in SMP and CC-NUMA servers produced by Sun, Solbourne and Fujitsu, among others, and designed for 64-bit operation. As of July 2016, the latest commercial high-end SPARC processors are Fujitsus SPARC64 X+ and SPARC64 XIfx, the SPARC architecture was heavily influenced by the earlier RISC designs including the RISC I and II from the University of California, Berkeley and the IBM801. These original RISC designs were minimalist, including as few features or op-codes as possible and this made them similar to the MIPS architecture in many ways, including the lack of instructions such as multiply or divide. Another feature of SPARC influenced by this early RISC movement is the delay slot. The SPARC processor usually contains as many as 160 general purpose registers, according to the Oracle SPARC Architecture 2015 specification an implementation may contain from 72 to 640 general-purpose 64-bit registers. At any point, only 32 of them are visible to software –8 are a set of global registers. These 24 registers form what is called a window, and at function call/return. Each window has 8 local registers and shares 8 registers with each of the adjacent windows, the shared registers are used for passing function parameters and returning values, and the local registers are used for retaining local values across function calls. Other architectures that include similar register file features include Intel i960, IA-64, the architecture has gone through several revisions. It gained hardware multiply and divide functionality in Version 8, 64-bit were added to the version 9 SPARC specification published in 1994. In SPARC Version 8, the floating point register file has 16 double precision registers, each of them can be used as two single precision registers, providing a total of 32 single precision registers. An odd-even number pair of double precision registers can be used as a quad precision register, SPARC Version 9 added 16 more double precision registers, but these additional registers can not be accessed as single precision registers. No SPARC CPU implements quad-precision operations in hardware as of 2004, tagged add and subtract instructions perform adds and subtracts on values checking that the bottom two bits of both operands are 0 and reporting overflow if they are not. This can be useful in the implementation of the run time for ML, Lisp, the endianness of the 32-bit SPARC V8 architecture is purely big-endian. The latter is used for accessing data from inherently little-endian devices. There have been three revisions of the architecture
12.
NeXTSTEP
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NeXTSTEP is a discontinued object-oriented, multitasking operating system based on UNIX. Although relatively unsuccessful at the time, it attracted interest from computer scientists and it was also the platform on which Tim Berners-Lee created the first web browser. After the purchase of NeXT by Apple, it became the source of the operating systems macOS, iOS, watchOS and tvOS. Many bundled macOS applications, such as TextEdit, Mail and Chess, are descendants of NeXTSTEP applications, the toolkits offer considerable power, and are the canonical development system for all of the software on the machine. NeXTSTEPs user interface is considered to be refined and consistent and it introduced the idea of the Dock and the Shelf. Additional kits were added to the line to make the system more attractive. These include Portable Distributed Objects, which allow easy remote invocation, and Enterprise Objects Framework, the kits made the system particularly interesting to custom application programmers, and NeXTSTEP had a long history in the financial programming community. A preview release of NeXTSTEP was shown with the launch of the NeXT Computer on October 12,1988, the first full release, NeXTSTEP1.0, shipped on September 18,1989. NeXTSTEP was later modified to separate the underlying operating system from the higher-level object libraries, the result was the OpenStep API, which ran on multiple underlying operating systems, including NeXTs own OPENSTEP, Windows NT and SUN Solaris. NeXTSTEPs legacy stands today in the form of its direct descendents, from day one, the operating system of NeXTSTEP was built upon Mach/BSD. It was built on 4. 3BSD Tahoe and it changed to 4. 3BSD Reno after the release of NeXTSTEP3.0. It changed to 4. 4BSD during the development of Rhapsody, the first web browser, WorldWideWeb, and the first ever app store were all invented on the NeXTSTEP platform. Some features and keyboard shortcuts now commonly found in web browsers can be traced back to NeXTSTEP conventions, the basic layout options of HTML1.0 and 2.0 are attributable to those features available in NeXTs Text class. Other games based on the Doom engine such as Heretic and its sequel Hexen by Raven Software as well as Strife by Rogue Entertainment were also developed on NeXT hardware using ids tools. Altsys made a NeXTSTEP application called Virtuoso, version 2 of which was ported to Mac OS, the modern Notebook interface for Mathematica, and the advanced spreadsheet Lotus Improv, were developed using NeXTSTEP. The software that controlled MCIs Friends and Family calling plan program was developed using NeXTSTEP, about the time of the release of NeXTSTEP3.2, NeXT partnered with Sun Microsystems to develop OpenStep. It is the product of an effort to separate the underlying operating system from the higher-level object libraries to create a cross-platform object-oriented API standard derived from NeXTSTEP, the OpenStep API targets multiple underlying operating systems, including NeXTs own OPENSTEP. Implementations of that standard were released for Suns Solaris, Windows NT, NeXTs implementation is called OPENSTEP for Mach and its first release superseded NeXTSTEP3.3 on NeXT, Sun and Intel IA-32 systems
13.
Mach kernel
–
Mach is a kernel developed at Carnegie Mellon University to support operating system research, primarily distributed and parallel computing. Mach is often mentioned as one of the earliest examples of a microkernel, however, not all versions of Mach are microkernels. Machs derivatives are the basis of the operating system kernels in GNU Hurd. The project at Carnegie Mellon ran from 1985 to 1994, ending with Mach 3.0, Mach was developed as a replacement for the kernel in the BSD version of Unix, so no new operating system would have to be designed around it. Experimental research on Mach appears to have ended, although Mach and these include NeXTSTEP and OpenStep, upon which macOS is based—all using the XNU operating system kernel which incorporates an earlier, non-microkernel, Mach as a major component. The Mach virtual memory management system was adopted in 4. 4BSD by the BSD developers at CSRG. Mach is the successor to Carnegie Mellons Accent kernel. The lead developer on the Mach project, Richard Rashid, has been working at Microsoft since 1991 in various top-level positions revolving around the Microsoft Research division. Another of the original Mach developers, Avie Tevanian, was head of software at NeXT. Rashid liked Giuses spelling Mach so much that it prevailed, a key concept in the original Unix operating system was the idea of a pipe. A pipe was an abstraction that allowed data to be moved from program to program using the command line, using pipes, users could link together multiple programs to complete tasks, feeding data through several small programs in turn. Pipes were built on the underlying input/output system and this system was, in turn, based on a model where drivers were expected to periodically block while they waited for tasks to complete. For instance, a driver might send a line of text to a line printer. In this case, the driver would indicate that it was blocked, in the pipes system the limited resource was memory, and when one program filled the memory assigned to the pipe, it would naturally block. Normally this would cause the program to run, emptying the pipe out again. However, the implementation of pipes as memory buffers meant data was being copied from program to program and this made the pipe concept unsuitable for tasks where quick turnaround or low latency was needed, as is the case in most device drivers. The operating system kernel and most core functionality was instead written as a large program. As the operating system added new functionality, the size and complexity of the kernel grew, Unix pipes offered a conceptual system that could be used to build arbitrarily complex solutions out of small interacting programs
14.
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
15.
Library (computing)
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In computer science, a library is a collection of non-volatile resources used by computer programs, often to develop software. These may include data, documentation, help data, message templates, pre-written code. In IBMs OS/360 and its successors they are referred to as partitioned data sets, a library is also a collection of implementations of behavior, written in terms of a language, that has a well-defined interface by which the behavior is invoked. For instance, people who want to write a higher level program can use a library to make system calls instead of implementing those system calls over and over again, in addition, the behavior is provided for reuse by multiple independent programs. A program invokes the library-provided behavior via a mechanism of the language, for example, in a simple imperative language such as C, the behavior in a library is invoked by using Cs normal function-call. What distinguishes the call as being to a library, versus being to function in the same program, is the way that the code is organized in the system. This distinction can gain a hierarchical notion when a program grows large, in that case, there may be internal libraries that are reused by independent sub-portions of the large program. The value of a lies in the reuse of the behavior. When a program invokes a library, it gains the behavior implemented inside that library without having to implement that behavior itself, libraries encourage the sharing of code in a modular fashion, and ease the distribution of the code. The behavior implemented by a library can be connected to the program at different program lifecycle phases. If the code of the library is accessed during the build of the invoking program, an alternative is to build the executable of the invoking program and distribute that, independently of the library implementation. The library behavior is connected after the executable has been invoked to be executed, either as part of the process of starting the execution, in this case the library is called a dynamic library. A dynamic library can be loaded and linked when preparing a program for execution, alternatively, in the middle of execution, an application may explicitly request that a module be loaded. Most compiled languages have a library although programmers can also create their own custom libraries. Most modern software systems provide libraries that implement the majority of the system services, such libraries have commoditized the services which a modern application requires. As such, most code used by modern applications is provided in these system libraries, the earliest programming concepts analogous to libraries were intended to separate data definitions from the program implementation. JOVIAL brought the COMPOOL concept to popular attention in 1959, although it adopted the idea from the large-system SAGE software, COBOL also included primitive capabilities for a library system in 1959, but Jean Sammet described them as inadequate library facilities in retrospect. Another major contributor to the library concept came in the form of the subprogram innovation of FORTRAN
16.
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
17.
Classic Mac OS
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This is a list of macOS components, features that are included in the current Mac operating system. Latest version 2.7 Automator is a developed by Apple Inc. Automator enables the repetition of tasks across a variety of programs, including Finder, Safari, Calendar, Contacts. It can also work with third-party applications such as Microsoft Office, the icon features a robot holding a pipe, a reference to pipelines, a computer science term for connected data workflows. Automator was first released with Mac OS X Tiger, Automator provides a graphical user interface for automating tasks without knowledge of programming or scripting languages. Tasks can be recorded as they are performed by the user or can be selected from a list, the output of the previous action can become the input to the next action. Automator comes with a library of Actions that act as individual steps in a Workflow document, a Workflow document is used to carry out repetitive tasks. Workflows can be saved and reused, unix command line scripts and AppleScripts can also be invoked as Actions. The actions are linked together in a Workflow, the Workflow can be saved as an application, Workflow file or a contextual menu item. Options can be set when the Workflow is created or when the Workflow is run, a workflow file created in Automator is saved in /Users//Library/Services. Latest version 10.8 Calculator is a calculator application made by Apple Inc. It has three modes, basic, scientific, and programmer, Basic includes a number pad, buttons for adding, subtracting, multiplying, and dividing, as well as memory keys. Scientific mode supports exponents and trigonometric functions, and programmer mode gives the user access to more options related to computer programming, Apple currently ships a different application called Grapher. Calculator has Reverse Polish notation support, and can speak the buttons pressed. The Calculator appeared first as an accessory in first version of Macintosh System for the 1984 Macintosh 128k. Its design was maintained with the basic math operations until the final release of classic Mac OS in 2002. A Dashboard Calculator widget is included in all versions of macOS from Mac OS X Tiger onwards and it only has the basic mode of its desktop counterpart. Since the release of OS X Yosemite, there is also a simple calculator widget available in the notifications area, since the release of Mac OS X Leopard, simple arithmetic functions can be calculated from Spotlight feature
18.
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
19.
IPhone
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IPhone is a line of smartphones designed and marketed by Apple Inc. They run Apples iOS mobile operating system, the first generation iPhone was released on June 29,2007, the most recent iPhone model is the iPhone 7, which was unveiled at a special event on September 7,2016. The user interface is built around the devices multi-touch screen, including a virtual keyboard, the iPhone has Wi-Fi and can connect to cellular networks. Other functionality, such as games, reference works, and social networking. As of January 2017, Apples App Store contained more than 2.2 million applications available for the iPhone, Apple has released ten generations of iPhone models, each accompanied by one of the ten major releases of the iOS operating system. The iPhone 5 featured a taller, 4-inch display and Apples newly introduced Lightning connector, in 2013, Apple released the 5S with improved hardware and a fingerprint reader, and the lower-cost 5C, a version of the 5 with colored plastic casings instead of metal. They were followed by the larger iPhone 6, with models featuring 4.7 and 5. 5-inch displays.5 mm headphone jack found on previous phones. The iPhones commercial success has been credited with reshaping the smartphone industry, the original iPhone was one of the first phones to use a design featuring a slate format with a touchscreen interface. Almost all modern smartphones have replicated this style of design, in the US, the iPhone holds the largest share of the smartphone market. As of late 2015, the iPhone had a 43. 6% market share, followed by Samsung, LG, Apple CEO Steve Jobs steered the original focus away from a tablet and towards a phone. Apple created the device during a collaboration with Cingular Wireless at the time—at an estimated development cost of US$150 million over thirty months. Apple rejected the design by committee approach that had yielded the Motorola ROKR E1, among other deficiencies, the ROKR E1s firmware limited storage to only 100 iTunes songs to avoid competing with Apples iPod nano. Jobs unveiled the iPhone to the public on January 9,2007, the passionate reaction to the launch of the iPhone resulted in sections of the media dubbing it the Jesus phone. Following this successful release in the US, the first generation iPhone was made available in the UK, France, and Germany in November 2007, on July 11,2008, Apple released the iPhone 3G in twenty-two countries, including the original six. Apple released the iPhone 3G in upwards of eighty countries and territories. Apple announced the iPhone 3GS on June 8,2009, along with plans to release it later in June, July, many would-be users objected to the iPhones cost, and 40% of users had household incomes over US$100,000. The back of the original first generation iPhone was made of aluminum with a black plastic accent, the iPhone 3G and 3GS feature a full plastic back to increase the strength of the GSM signal. The iPhone 3G was available in an 8 GB black model, the iPhone 3GS was available in both colors, regardless of storage capacity
20.
IPad
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IPad is a line of tablet computers designed, developed and marketed by Apple Inc. which run the iOS mobile operating system. The first iPad was released on April 3,2010, the most recent iPad models are the 9. 7-inch iPad Pro released on March 31,2016, the user interface is built around the devices multi-touch screen, including a virtual keyboard. The iPad includes built-in Wi-Fi and cellular connectivity on select models, as of January 2015, there have been over 250 million iPads sold. IPad tablets are second most popular, by sales, against Android-based ones, since 2013, an iPad can shoot video, take photos, play music, and perform Internet functions such as web-browsing and emailing. Other functions – games, reference, GPS navigation, social networking, as of March 2016, the App Store has more than one million apps for the iPad by Apple and third parties. There have been six versions of the iPad, the first generation established design precedents, such as the 9. 7-inch screen size and button placement, that have persisted through all models. The third generation added a Retina Display, the new Apple A5X processor with a graphics processor, a 5-megapixel camera, HD 1080p video recording, voice dictation. The fourth generation added the Apple A6X processor and replaces the 30-pin connector with an all-digital Lightning connector, the iPad Air added the Apple A7 processor and the Apple M7 motion coprocessor, and reduced the thickness for the first time since the iPad 2. The iPad Air 2 added the Apple A8X processor, the Apple M8 motion coprocessor, an 8-megapixel camera, and the Touch ID fingerprint sensor, there have been four versions of the iPad Mini. The first generation features a screen size of 7.9 inches and features similar internal specifications as the iPad 2 except it uses the Lightning connector. The iPad Mini 2 features the Retina Display, the Apple A7 processor, the iPad Mini 3 features the Touch ID fingerprint sensor. The iPad Mini 4 features the Apple A8 and the Apple M8 motion coprocessor, Apple co-founder Steve Jobs said in a 1983 speech that the companys strategy is really simple. What we want to do is we want to put a great computer in a book that you can carry around with you. And we really want to do it with a link in it so you don’t have to hook up to anything and you’re in communication with all of these larger databases. Apples first tablet computer was the Newton MessagePad 100, introduced in 1993, powered by an ARM6 processor core developed by ARM, Apple also developed a prototype PowerBook Duo based tablet, the PenLite, but decided not to sell it in order to avoid hurting MessagePad sales. Apple released several more Newton-based PDAs, the one, the MessagePad 2100, was discontinued in 1998. Apple re-entered the mobile-computing markets in 2007 with the iPhone, smaller than the iPad, but featuring a camera and mobile phone, it pioneered the multi-touch finger-sensitive touchscreen interface of Apples iOS mobile operating system. By late 2009, the release had been rumored for several years
21.
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
22.
Common Object Request Broker Architecture
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The Common Object Request Broker Architecture is a standard defined by the Object Management Group designed to facilitate the communication of systems that are deployed on diverse platforms. CORBA enables collaboration between systems on different operating systems, programming languages, and computing hardware, CORBA uses an object-oriented model although the systems that use the CORBA do not have to be object-oriented. CORBA is an example of the distributed object paradigm, CORBA enables communication between software written in different languages and running on different computers. Implementation details from specific operating systems, programming languages, and hardware platforms are all removed from the responsibility of developers who use CORBA, CORBA normalizes the method-call semantics between application objects residing either in the same address-space or in remote address-spaces. Version 1.0 was released in October 1991, CORBA uses an interface definition language to specify the interfaces that objects present to the outer world. CORBA then specifies a mapping from IDL to an implementation language like C++ or Java. Standard mappings exist for Ada, C, C++, C++11, COBOL, Java, Lisp, PL/I, Object Pascal, Python, Ruby, non-standard mappings exist for C#, Erlang, Perl, Tcl and Visual Basic implemented by object request brokers written for those languages. The CORBA specification dictates there shall be an ORB through which an application would interact with other objects, the Object Adapter is used to register instances of the generated code classes. This step is necessary in order to enforce CORBA semantics and provide a user process for interfacing with the CORBA infrastructure. Some IDL mappings are more difficult to use than others, for example, due to the nature of Java, the IDL-Java mapping is rather straightforward and makes usage of CORBA very simple in a Java application. This is also true of the IDL to Python mapping, the C++ mapping requires the programmer to learn datatypes that predate the C++ Standard Template Library. By contrast, the C++11 mapping is easier to use, since the C language is not object-oriented, the IDL to C mapping requires a C programmer to manually emulate object-oriented features. Typically, an ORB implementation includes a tool called an IDL compiler that translates the IDL interface into the language for use in that part of the system. A traditional compiler then compiles the code to create the linkable-object files for use in the application. This diagram illustrates how the code is used within the CORBA infrastructure. The CORBA specification further addresses data typing, exceptions, network protocols, communication timeouts, for example, Normally the server side has the Portable Object Adapter that redirects calls either to the local servants or to the other servers. This paragraph present the history of versions released for the CORBA standard, a servant is the invocation target containing methods for handling the remote method invocations. In the newer CORBA versions, the object is split into the object
23.
X Window System
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The X Window System is a windowing system for bitmap displays, common on UNIX-like computer operating systems. X provides the framework for a GUI environment, drawing and moving windows on the display device and interacting with a mouse. X does not mandate the user interface – this is handled by individual programs, as such, the visual styling of X-based environments varies greatly, different programs may present radically different interfaces. X originated at the Massachusetts Institute of Technology in 1984, the protocol has been version 11 since September 1987. The X. Org Foundation leads the X project, with the current reference implementation, X. Org Server, available as free and open source software under the MIT License, X is an architecture-independent system for remote graphical user interfaces and input device capabilities. Each person using a terminal has the ability to interact with the display with any type of user input device. X provides the framework, or primitives, for building such GUI environments, drawing and moving windows on the display and interacting with a mouse. X does not mandate the user interface, individual client programs handle this, programs may use Xs graphical abilities with no user interface. As such, the styling of X-based environments varies greatly. Unlike most earlier display protocols, X was specifically designed to be used over network connections rather than on an integral or attached display device. X features network transparency, which means an X program running on a computer somewhere on a network can display its user interface on an X server running on other computer on the network. The fact that the server is applied to the software in front of the user is often surprising to users accustomed to their programs being clients to services on remote computers. Xs network protocol is based on X command primitives and this approach allows both 2D and 3D operations by an X client application which might be running on a different computer to still be fully accelerated on the X servers display. X provides no support for audio, several projects exist to fill this niche. X uses a model, an X server communicates with various client programs. The server accepts requests for graphical output and sends back user input, a client and server can even communicate securely over the Internet by tunneling the connection over an encrypted network session. An X client itself may emulate an X server by providing services to other clients. This is known as X nesting, open-source clients such as Xnest and Xephyr support such X nesting
24.
Window manager
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A window manager is system software that controls the placement and appearance of windows within a windowing system in a graphical user interface. Most window managers are designed to provide a desktop environment. Few window managers are designed with a distinction between the windowing system and the window manager. Every graphical user interface based on a windows metaphor has some form of window management, in practice, the elements of this functionality vary greatly. Elements usually associated with window managers allow the user to open, close, minimize, maximize, move, resize, many window managers also come with various utilities and features, e. g. docks, task bars, program launchers, desktop icons, and wallpaper. On systems using the X window system, there is a distinction between the window manager and the windowing system. Strictly speaking, an X window manager does not directly interact with hardware, mice. Users of the X Window System have the ability to use many different window managers – Metacity, used in GNOME2, and KWin, used in KDE Plasma Workspaces. Since many window managers are modular, people can use others, such as Compiz, sawfish and awesome on the other hand are extensible window managers offering exacting window control. Components of different window managers can even be mixed and matched, for example, Window managers under the X window system adopt applications from the root window and re-parent them to window decorations. Re-parenting can also be used to add the contents of one window to another, for example, a flash player application can be re-parented to a browser window, and can appear to the user as supposedly being part of that program. Re-parenting window managers can therefore arrange one or more programs into the same window, Microsoft Windows has provided an integrated stacking window manager since Windows 2.0, Windows Vista introduced the compositing Desktop Window Manager as an optional hardware-accelerated alternative. Since Windows 8, the Desktop Window Manager can no longer be disabled, the Windows window manager can also act as an X window manager through Cygwin/X in multiwindow mode. Note that Microsoft and X Window System use different terms to describe similar concepts, for example, there is no specific word for window manager functionality in Windows. Window managers are often divided into three or more classes, which describe how windows are drawn and updated, Compositing window managers let all windows be created and drawn separately and then put together and displayed in various 2D and 3D environments. The most advanced compositing window managers allow for a deal of variety in interface look and feel. All window managers that have overlapping windows and are not compositing window managers are stacking window managers, stacking window managers allow windows to overlap by drawing background windows first, which is referred to as painters algorithm. Changes sometimes require that all windows be re-stacked or repainted, which usually involves redrawing every window, tiling window managers paint all windows on-screen by placing them side by side or above and below each other, so that no window ever covers another
25.
Dock (macOS)
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The Dock is a prominent feature of the graphical user interface of the macOS operating system. It is used to launch applications and to switch between running applications, the Dock is also a prominent feature of macOSs predecessor NeXTSTEP and OpenStep operating systems. The earliest known implementations of a dock are found in operating systems such as RISC OS, IOS has its own version of the Dock for iPhone, iPod Touch and iPad. Apple applied for a US patent for the design of the Dock in 1999 and was granted the patent in October 2008, nine years later. Applications can be added to and removed from the Dock by drag and drop, except for the Finder, the Trash icon is also a permanent fixture at the right end. Part of the macOS Core Services, Dock. app is located at /System/Library/CoreServices/, in NeXTSTEP and OpenStep, the Dock is an application launcher that holds icons for frequently used programs. The icon for the Workspace Manager and the Recycler are always visible, the Dock indicates if a program is not running by showing an ellipsis below its icon. If the program is running, there isnt an ellipsis on the icon, in macOS, running applications have been variously identified by a small black triangle a blue-tinted luminous dot, a horizontal light bar, and a simple black or white dot. In macOS, however, the Dock is used as a repository for any program or file in the operating system and it can hold any number of items and resizes them dynamically to fit while using magnification to clarify smaller resized items. By default, it appears on the edge of the screen. Applications that do not normally keep icons in the Dock will still appear there when running and these features are unlike those of the dock in the NeXT operating systems where the capacity of the Dock is dependent on display resolution. This may be an attempt to recover some Shelf functionality since macOS inherits no other such technology from NeXTSTEP, the changes to the dock bring its functionality also close to that of Apples Newton OS Button Bar, as found in the MessagePad 2x00 series and the likes. Applications could be dragged in and out of the Extras Drawer, also, when the screen was put into landscape mode, the user could choose to position the Button Bar at the right or left side of the screen, just like the Dock in macOS. The macOS Dock also has extended menus that control applications without making them visible on screen, other Applications include changing the status of an online alias or automatically saving the changes that have been made in a document. Docklings can also be opened by using the button, if the mouse has one. In Mac OS X Leopard, docklings were replaced by Stacks, Stacks stack files into a small organized folder on the Dock, and they can be opened by left-clicking. Stacks could be shown in three ways, a fan, a grid, or a list, which is similar to docklings, in grid view, the folders in that stack can be opened directly in that stack without the need to open Finder. In iOS, the dock is used to store applications and, since iOS4, unlike the macOS dock, a maximum of 4 icons can be placed in the dock on the iPhone and the iPod Touch
26.
Endianness
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Endianness refers to the sequential order used to numerically interpret a range of bytes in computer memory as a larger, composed word value. It also describes the order of transmission over a digital link. Little-endian format reverses the order of the sequence and stores the least significant byte at the first location with the most significant byte being stored last. The order of bits within a byte can also have endianness, however, both big and little forms of endianness are widely used in digital electronics. As examples, the IBM z/Architecture mainframes use big-endian while the Intel x86 processors use little-endian, the designers chose endianness in the 1960s and 1970s respectively. Big-endian is the most common format in data networking, fields in the protocols of the Internet protocol suite, such as IPv4, IPv6, TCP, for this reason, big-endian byte order is also referred to as network byte order. Little-endian storage is popular for microprocessors, in due to significant influence on microprocessor designs by Intel Corporation. Mixed forms also exist, for instance the ordering of bytes in a 16-bit word may differ from the ordering of 16-bit words within a 32-bit word, such cases are sometimes referred to as mixed-endian or middle-endian. There are also some bi-endian processors that operate in either little-endian or big-endian mode, big-endianness may be demonstrated by writing a decimal number, say one hundred twenty-three, on paper in the usual positional notation understood by a numerate reader,123. The digits are written starting from the left and to the right, with the most significant digit,1 and this is analogous to the lowest address of memory being used first. This is an example of a big-endian convention taken from daily life, the little-endian way of writing the same number, one hundred twenty-three, would place the hundreds-digit 1 in the right-most position,321. A person following conventional big-endian place-value order, who is not aware of this ordering, would read a different number. Endianness in computing is similar, but it applies to the ordering of bytes. The illustrations to the right, where a is a memory address, danny Cohen introduced the terms Little-Endian and Big-Endian for byte ordering in an article from 1980. Computer memory consists of a sequence of storage cells, each cell is identified in hardware and software by its memory address. If the total number of cells in memory is n. Computer programs often use data structures of fields that may consist of data than is stored in one memory cell. For the purpose of this article where its use as an operand of an instruction is relevant, in addition to that, it has to be of numeric type in some positional number system
27.
Intel
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Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California that was founded by Gordon Moore and Robert Noyce. It is the worlds largest and highest valued semiconductor chip makers based on revenue, and is the inventor of the x86 series of microprocessors, Intel supplies processors for computer system manufacturers such as Apple, Lenovo, HP, and Dell. Intel Corporation was founded on July 18,1968, by semiconductor pioneers Robert Noyce and Gordon Moore, the companys name was conceived as portmanteau of the words integrated and electronics. The fact that intel is the term for intelligence information made the name appropriate. Intel was a developer of SRAM and DRAM memory chips. Although Intel created the worlds first commercial microprocessor chip in 1971, during the 1990s, Intel invested heavily in new microprocessor designs fostering the rapid growth of the computer industry. The Open Source Technology Center at Intel hosts PowerTOP and LatencyTOP, and supports other projects such as Wayland, Intel Array Building Blocks, and Threading Building Blocks. Client Computing Group – 55% of 2016 revenues – produces hardware components used in desktop, data Center Group – 29% of 2016 revenues – produces hardware components used in server, network, and storage platforms. Internet of Things Group – 5% of 2016 revenues – offers platforms designed for retail, transportation, industrial, buildings, non-Volatile Memory Solutions Group – 4% of 2016 revenues – manufactures NAND flash memory products primarily used in solid-state drives. Intel Security Group – 4% of 2016 revenues – produces software, particularly security, programmable Solutions Group – 3% of 2016 revenues – manufactures programmable semiconductors. In 2016, Dell accounted for 15% of Intels total revenues, Lenovo accounted for 13% of total revenues, in the 1980s, Intel was among the top ten sellers of semiconductors in the world. In 1991, Intel became the biggest chip maker by revenue and has held the position ever since, other top semiconductor companies include TSMC, Advanced Micro Devices, Samsung, Texas Instruments, Toshiba and STMicroelectronics. Competitors in PC chip sets include Advanced Micro Devices, VIA Technologies, Silicon Integrated Systems, however, the cross-licensing agreement is canceled in the event of an AMD bankruptcy or takeover. Some smaller competitors such as VIA Technologies produce low-power x86 processors for small factor computers, however, the advent of such mobile computing devices, in particular, smartphones, has in recent years led to a decline in PC sales. Since over 95% of the worlds smartphones currently use processors designed by ARM Holdings, ARM is also planning to make inroads into the PC and server market. Intel has been involved in disputes regarding violation of antitrust laws. Intel was founded in Mountain View, California in 1968 by Gordon E. Moore, a chemist, and Robert Noyce, arthur Rock helped them find investors, while Max Palevsky was on the board from an early stage. Moore and Noyce had left Fairchild Semiconductor to found Intel, Rock was not an employee, but he was an investor and was chairman of the board
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Graphical user interface
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GUIs were introduced in reaction to the perceived steep learning curve of command-line interfaces, which require commands to be typed on a computer keyboard. The actions in a GUI are usually performed through direct manipulation of the graphical elements, beyond computers, GUIs are used in many handheld mobile devices such as MP3 players, portable media players, gaming devices, smartphones and smaller household, office and industrial controls. Designing the visual composition and temporal behavior of a GUI is an important part of application programming in the area of human–computer interaction. Its goal is to enhance the efficiency and ease of use for the logical design of a stored program. Methods of user-centered design are used to ensure that the language introduced in the design is well-tailored to the tasks. The visible graphical interface features of an application are sometimes referred to as chrome or GUI, typically, users interact with information by manipulating visual widgets that allow for interactions appropriate to the kind of data they hold. The widgets of an interface are selected to support the actions necessary to achieve the goals of users. A model–view–controller allows a structure in which the interface is independent from and indirectly linked to application functions. This allows users to select or design a different skin at will, good user interface design relates to users more, and to system architecture less. Large widgets, such as windows, usually provide a frame or container for the main presentation content such as a web page, smaller ones usually act as a user-input tool. A GUI may be designed for the requirements of a market as application-specific graphical user interfaces. By the 1990s, cell phones and handheld game systems also employed application specific touchscreen GUIs, newer automobiles use GUIs in their navigation systems and multimedia centers, or navigation multimedia center combinations. Sample graphical desktop environments A GUI uses a combination of technologies and devices to provide a platform that users can interact with, a series of elements conforming a visual language have evolved to represent information stored in computers. This makes it easier for people with few computer skills to work with, the most common combination of such elements in GUIs is the windows, icons, menus, pointer paradigm, especially in personal computers. The WIMP style of interaction uses a virtual device to represent the position of a pointing device, most often a mouse. Available commands are compiled together in menus, and actions are performed making gestures with the pointing device, a window manager facilitates the interactions between windows, applications, and the windowing system. The windowing system handles hardware devices such as pointing devices, graphics hardware, window managers and other software combine to simulate the desktop environment with varying degrees of realism. Smaller mobile devices such as personal assistants and smartphones typically use the WIMP elements with different unifying metaphors, due to constraints in space
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PostScript
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PostScript is a page description language in the electronic publishing and desktop publishing business. It is a typed, concatenative programming language and was created at Adobe Systems by John Warnock, Charles Geschke, Doug Brotz, Ed Taft. The concepts of the PostScript language were seeded in 1976 when John Warnock was working at Evans & Sutherland, at that time John Warnock was developing an interpreter for a large three-dimensional graphics database of New York harbor. Warnock conceived the Design System language to process the graphics, concurrently, researchers at Xerox PARC had developed the first laser printer and had recognized the need for a standard means of defining page images. In 1975-76 Bob Sproull and William Newman developed the Press format, but Press, a data format rather than a language, lacked flexibility, and PARC mounted the Interpress effort to create a successor. In 1978 Evans & Sutherland asked Warnock to move from the San Francisco Bay Area to their headquarters in Utah. He then joined Xerox PARC to work with Martin Newell and they rewrote Design System to create J & M which was used for VLSI design and the investigation of type and graphics printing. This work later evolved and expanded into the Interpress language, Warnock left with Chuck Geschke and founded Adobe Systems in December 1982. They, together with Doug Brotz, Ed Taft and Bill Paxton created a language, similar to Interpress, called PostScript. At about this time they were visited by Steve Jobs, who urged them to adapt PostScript to be used as the language for driving laser printers. In March 1985, the Apple LaserWriter was the first printer to ship with PostScript, the combination of technical merits and widespread availability made PostScript a language of choice for graphical output for printing applications. For a time an interpreter for the PostScript language was a component of laser printers. However, the cost of implementation was high, computers output raw PS code that would be interpreted by the printer into an image at the printers natural resolution. This required high performance microprocessors and ample memory, the LaserWriter used a 12 MHz Motorola 68000, making it faster than any of the Macintosh computers to which it attached. When the laser printer engines themselves cost over a thousand dollars the added cost of PS was marginal, the first version of the PostScript language was released to the market in 1984. The term Level 1 was added when Level 2 was introduced, PostScript 3 came at the end of 1997, and along with many new dictionary-based versions of older operators, introduced better color handling, and new filters. Prior to the introduction of PostScript, printers were designed to print character output given the text—typically in ASCII—as input and this changed to some degree with the increasing popularity of dot matrix printers. The characters on these systems were drawn as a series of dots, dot matrix printers also introduced the ability to print raster graphics
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Distributed object communication
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In a distributed computing environment, distributed object communication realizes communication between distributed objects. The main role is to allow objects to data and invoke methods on remote objects. Invoking a method on an object is known as remote method invocation or remote invocation. The widely used approach on how to implement the communication channel is realized by using stubs and they are generated objects whose structure and behavior depends on chosen communication protocol, but in general provide additional functionality that ensures reliable communication over the network. In RMI, a stub is defined by the programmer as an interface, the rmic compiler uses this to create the class stub. The skeleton is defined in a class which implements the interface stub, when a caller wants to perform remote call on the called object, it delegates requests to its stub which initiates communication with the remote skeleton. Consequently, the stub passes caller arguments over the network to the server skeleton, the skeleton then passes received data to the called object, waits for a response and returns the result to the client stub. Note, there is no communication between the caller and the called object. This functionality, that ensures reliable communication channel over the network, has moved to the stub. The client side object participating in distributed object communication is known as a stub or proxy, the stub acts as a gateway for client side objects and all outgoing requests to server side objects that are routed through it. The stub wraps client object functionality and by adding the network logic ensures the communication channel between client and server. The stub can be written up manually or generated automatically depending on chosen communication protocol, a skeleton acts as gateway for server side objects and all incoming clients requests are routed through it. The skeleton wraps server object functionality and exposes it to the clients, an Architectural View of Distributed Objects and Components in CORBA, Java RMI, and COM/DCOM, Software Concepts & Tools, January,1998. Druschel, Peter Distributed Program Construction Farley, Jim, Java Distributed Computing, OReilly, January,1998. Research Papers, Distributed Systems Research Group, Charles University Prague
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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
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Microsoft Excel
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Microsoft Excel is a spreadsheet developed by Microsoft for Windows, macOS, Android and iOS. It features calculation, graphing tools, pivot tables, and a programming language called Visual Basic for Applications. It has been a widely applied spreadsheet for these platforms, especially since version 5 in 1993. Excel forms part of Microsoft Office, Microsoft Excel has the basic features of all spreadsheets, using a grid of cells arranged in numbered rows and letter-named columns to organize data manipulations like arithmetic operations. It has a battery of supplied functions to answer statistical, engineering, in addition, it can display data as line graphs, histograms and charts, and with a very limited three-dimensional graphical display. It allows sectioning of data to view its dependencies on various factors for different perspectives, Excel was not designed to be used as a database. Microsoft allows for a number of optional command-line switches to control the manner in which Excel starts, the Windows version of Excel supports programming through Microsofts Visual Basic for Applications, which is a dialect of Visual Basic. Programming with VBA allows spreadsheet manipulation that is awkward or impossible with standard spreadsheet techniques, programmers may write code directly using the Visual Basic Editor, which includes a window for writing code, debugging code, and code module organization environment. A common and easy way to generate VBA code is by using the Macro Recorder, the Macro Recorder records actions of the user and generates VBA code in the form of a macro. These actions can then be repeated automatically by running the macro, the macros can also be linked to different trigger types like keyboard shortcuts, a command button or a graphic. The actions in the macro can be executed from these types or from the generic toolbar options. The VBA code of the macro can also be edited in the VBE, advanced users can employ user prompts to create an interactive program, or react to events such as sheets being loaded or changed. Macro Recorded code may not be compatible between Excel versions, some code that is used in Excel 2010 can not be used in Excel 2003. Making a Macro that changes the colors and making changes to other aspects of cells may not be backward compatible. User-created VBA subroutines execute these actions and operate like macros generated using the macro recorder, from its first version Excel supported end user programming of macros and user defined functions.0. Beginning with version 5.0 Excel recorded macros in VBA by default, after version 5.0 that option was discontinued. All versions of Excel, including Excel 2010 are capable of running an XLM macro, Excel supports charts, graphs, or histograms generated from specified groups of cells. The generated graphic component can either be embedded within the current sheet and these displays are dynamically updated if the content of cells change
