Red Hat, Inc. is an American multinational software company providing open-source software products to the enterprise community. Founded in 1993, Red Hat has its corporate headquarters in Raleigh, North Carolina, with other offices worldwide. Red Hat has become associated to a large extent with its enterprise operating system Red Hat Enterprise Linux and with the acquisition of open-source enterprise middleware vendor JBoss. Red Hat offers Red Hat Virtualization, an enterprise virtualization product. Red Hat provides storage, operating system platforms, applications, management products, support and consulting services. Red Hat creates and contributes to many free software projects, it has acquired several proprietary software product codebases through corporate mergers and acquisitions and has released such software under open-source licenses. As of March 2016, Red Hat is the second largest corporate contributor to the Linux kernel version 4.14 after Intel. On October 28, 2018, IBM announced its intent to acquire Red Hat for $34 billion.
In 1993, Bob Young incorporated the ACC Corporation, a catalog business that sold Linux and Unix software accessories. In 1994, Marc Ewing created his own Linux distribution. Ewing released the software in October, it became known as the Halloween release. Young bought Ewing's business in 1995, the two merged to become Red Hat Software, with Young serving as chief executive officer. Red Hat went public on August 11, 1999, achieving the eighth-biggest first-day gain in the history of Wall Street. Matthew Szulik succeeded Bob Young as CEO in December of that year. Bob Young went on to found the online print on demand and self-publishing company, Lulu in 2002. On November 15, 1999, Red Hat acquired Cygnus Solutions. Cygnus provided commercial support for free software and housed maintainers of GNU software products such as the GNU Debugger and GNU Binutils. One of the founders of Cygnus, Michael Tiemann, became the chief technical officer of Red Hat and by 2008 the vice president of open-source affairs.
Red Hat acquired WireSpeed, C2Net and Hell's Kitchen Systems. In February 2000, InfoWorld awarded Red Hat its fourth consecutive "Operating System Product of the Year" award for Red Hat Linux 6.1. Red Hat acquired Planning Technologies, Inc in 2001 and AOL's iPlanet directory and certificate-server software in 2004. Red Hat moved its headquarters from Durham to North Carolina State University's Centennial Campus in Raleigh, North Carolina in February 2002. In the following month Red Hat introduced Red Hat Linux Advanced Server renamed Red Hat Enterprise Linux. Dell, IBM, HP and Oracle Corporation announced their support of the platform. In December 2005, CIO Insight magazine conducted its annual "Vendor Value Survey", in which Red Hat ranked #1 in value for the second year in a row. Red Hat stock became part of the NASDAQ-100 on December 19, 2005. Red Hat acquired open-source middleware provider JBoss on June 5, 2006, JBoss became a division of Red Hat. On September 18, 2006, Red Hat released the Red Hat Application Stack, which integrated the JBoss technology and, certified by other well-known software vendors.
On December 12, 2006, Red Hat stock moved from trading on NASDAQ to the New York Stock Exchange. In 2007 Red Hat made an agreement with Exadel to distribute its software. On March 15, 2007, Red Hat released Red Hat Enterprise Linux 5, in June acquired Mobicents. On March 13, 2008, Red Hat acquired Amentra, a provider of systems integration services for service-oriented architecture, business process management, systems development and enterprise data services. On July 27, 2009, Red Hat replaced CIT Group in Standard and Poor's 500 stock index, a diversified index of 500 leading companies of the U. S. economy. This was reported as a major milestone for Linux. On December 15, 2009, it was reported that Red Hat will pay US$8.8 million to settle a class action lawsuit related to the restatement of financial results from July 2004. The suit had been pending in U. S. District Court for the Eastern District of North Carolina. Red Hat reached the proposed settlement agreement and recorded a one-time charge of US$8.8 million for the quarter that ended Nov. 30.
On January 10, 2011, Red Hat announced that it would expand its headquarters in two phases, adding 540 employees to the Raleigh operation, investing over US$109 million. The state of North Carolina is offering up to US$15 million in incentives; the second phase involves "expansion into new technologies such as software visualization and technology cloud offerings". On August 25, 2011, Red Hat announced it would move about 600 employees from the N. C. State Centennial Campus to Two Progress Plaza downtown. A ribbon cutting ceremony was held June 2013, in the re-branded Red Hat Headquarters. In 2012, Red Hat became the first one-billion dollar open-source company, reaching US$1.13 billion in annual revenue during its fiscal year. Red Hat passed the $2 billion benchmark in 2015; as of February 2018 the company's annual revenue was nearly $3 billion. On October 16, 2015, Red Hat announced its acquisition of IT automation startup Ansible, rumored for an estimated $100 million USD. In May 2018, Red Hat acquired CoreOS.
On October 28, 2018, IBM announced its intent to acquire Red Hat for US$34 billion, in one of its largest-ever acquisitions. The company will operate out of IBM's Hybrid Cloud division. Red Hat's lead advisor was Guggenheim Securities LLC. Red Hat sponsors the Fedora Project, a community-supported free software project that aims to promote the rapid progress of free and open-source software and conten
In software engineering, a domain model is a conceptual model of the domain that incorporates both behaviour and data. In ontology engineering, a domain model is a formal representation of a knowledge domain with concepts, datatypes and rules grounded in a description logic. A domain model is a system of abstractions that describes selected aspects of a sphere of knowledge, influence or activity; the model can be used to solve problems related to that domain. The domain model is a representation of meaningful real-world concepts pertinent to the domain that need to be modeled in software; the concepts include the data involved in the business and rules the business uses in relation to that data. A domain model uses the vocabulary of the domain, thus allowing a representation of the model to be communicated to non-technical stakeholders, it should not refer to any technical implementations such as databases or software components that are being designed. A domain model is implemented as an object model within a layer that uses a lower-level layer for persistence and "publishes" an API to a higher-level layer to gain access to the data and behavior of the model.
In the Unified Modeling Language, a class diagram is used to represent the domain model. Domain-driven design Domain layer Feature-driven development Logical data model Problem domain Domain driven development Domain Modelling article
Open-source software is a type of computer software in which source code is released under a license in which the copyright holder grants users the rights to study and distribute the software to anyone and for any purpose. Open-source software may be developed in a collaborative public manner. Open-source software is a prominent example of open collaboration. Open-source software development generates an more diverse scope of design perspective than any company is capable of developing and sustaining long term. A 2008 report by the Standish Group stated that adoption of open-source software models have resulted in savings of about $60 billion per year for consumers. In the early days of computing and developers shared software in order to learn from each other and evolve the field of computing; the open-source notion moved to the way side of commercialization of software in the years 1970-1980. However, academics still developed software collaboratively. For example Donald Knuth in 1979 with the TeX typesetting system or Richard Stallman in 1983 with the GNU operating system.
In 1997, Eric Raymond published The Cathedral and the Bazaar, a reflective analysis of the hacker community and free-software principles. The paper received significant attention in early 1998, was one factor in motivating Netscape Communications Corporation to release their popular Netscape Communicator Internet suite as free software; this source code subsequently became the basis behind SeaMonkey, Mozilla Firefox and KompoZer. Netscape's act prompted Raymond and others to look into how to bring the Free Software Foundation's free software ideas and perceived benefits to the commercial software industry, they concluded that FSF's social activism was not appealing to companies like Netscape, looked for a way to rebrand the free software movement to emphasize the business potential of sharing and collaborating on software source code. The new term they chose was "open source", soon adopted by Bruce Perens, publisher Tim O'Reilly, Linus Torvalds, others; the Open Source Initiative was founded in February 1998 to encourage use of the new term and evangelize open-source principles.
While the Open Source Initiative sought to encourage the use of the new term and evangelize the principles it adhered to, commercial software vendors found themselves threatened by the concept of distributed software and universal access to an application's source code. A Microsoft executive publicly stated in 2001 that "open source is an intellectual property destroyer. I can't imagine something that could be worse than this for the software business and the intellectual-property business." However, while Free and open-source software has played a role outside of the mainstream of private software development, companies as large as Microsoft have begun to develop official open-source presences on the Internet. IBM, Oracle and State Farm are just a few of the companies with a serious public stake in today's competitive open-source market. There has been a significant shift in the corporate philosophy concerning the development of FOSS; the free-software movement was launched in 1983. In 1998, a group of individuals advocated that the term free software should be replaced by open-source software as an expression, less ambiguous and more comfortable for the corporate world.
Software licenses grant rights to users which would otherwise be reserved by copyright law to the copyright holder. Several open-source software licenses have qualified within the boundaries of the Open Source Definition; the most prominent and popular example is the GNU General Public License, which "allows free distribution under the condition that further developments and applications are put under the same licence", thus free. The open source label came out of a strategy session held on April 7, 1998 in Palo Alto in reaction to Netscape's January 1998 announcement of a source code release for Navigator. A group of individuals at the session included Tim O'Reilly, Linus Torvalds, Tom Paquin, Jamie Zawinski, Larry Wall, Brian Behlendorf, Sameer Parekh, Eric Allman, Greg Olson, Paul Vixie, John Ousterhout, Guido van Rossum, Philip Zimmermann, John Gilmore and Eric S. Raymond, they used the opportunity before the release of Navigator's source code to clarify a potential confusion caused by the ambiguity of the word "free" in English.
Many people claimed that the birth of the Internet, since 1969, started the open-source movement, while others do not distinguish between open-source and free software movements. The Free Software Foun
An operating system is system software that manages computer hardware and software resources and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may include accounting software for cost allocation of processor time, mass storage and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is executed directly by the hardware and makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computer – from cellular phones and video game consoles to web servers and supercomputers; the dominant desktop operating system is Microsoft Windows with a market share of around 82.74%. MacOS by Apple Inc. is in second place, the varieties of Linux are collectively in third place. In the mobile sector, use in 2017 is up to 70% of Google's Android and according to third quarter 2016 data, Android on smartphones is dominant with 87.5 percent and a growth rate 10.3 percent per year, followed by Apple's iOS with 12.1 percent and a per year decrease in market share of 5.2 percent, while other operating systems amount to just 0.3 percent.
Linux distributions are dominant in supercomputing sectors. Other specialized classes of operating systems, such as embedded and real-time systems, exist for many applications. A single-tasking system can only run one program at a time, while a multi-tasking operating system allows more than one program to be running in concurrency; this is achieved by time-sharing, where the available processor time is divided between multiple processes. These processes are each interrupted in time slices by a task-scheduling subsystem of the operating system. Multi-tasking may be characterized in 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, such as Solaris and Linux—as well as non-Unix-like, such as AmigaOS—support preemptive multitasking. 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 multi-user operating system extends the basic concept of multi-tasking with facilities that identify processes and resources, such as disk space, belonging to multiple users, the system permits multiple users to interact with the system at the same time. Time-sharing operating systems schedule tasks for efficient use of the system and may include accounting software for cost allocation of processor time, mass storage and other resources to multiple users. 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 group work in cooperation, they form a distributed system.
In an OS, distributed and cloud computing context, templating refers to creating a single virtual machine image as a guest operating system saving it as a tool for multiple running virtual machines. The technique is used both in virtualization and cloud computing management, 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. They are able to operate with a limited number of resources, they are compact and efficient by design. Windows CE and Minix 3 are some examples of embedded operating systems. A real-time operating system is an operating 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, it uses specialized scheduling algorithms so that a deterministic nature of behavior is achieved. An event-driven system switches between tasks based on their priorities or external events while time-sharing operating systems switch tasks based on clock interrupts.
A library operating system is one in which the services that a typical operating system provides, such as networking, are provided in the form of libraries and composed with the application and configuration code to construct a unikernel: a specialized, single address space, machine image that can be deployed to cloud or embedded environments. 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 automatically run different programs in succession to speed up processing. Operating systems did not exist in their more complex forms until the early 1960s. Hardware features were added, that enabled use of runtime libraries and parallel processing; when personal computers became popular in the 1980s, operating systems were made for them similar in concept to those used on larger computers. In the 1940s, the earliest electronic digital systems had no operating systems.
Electronic systems of this time were programmed on rows of mechanical switches or by jumper wires on plug boards. These were special-purpose systems that, for example, generated ballistics tables for the military or controlled the pri
A computing platform or digital platform is the environment in which a piece of software is executed. It may be the hardware or the operating system a web browser and associated application programming interfaces, or other underlying software, as long as the program code is executed with it. Computing platforms have different abstraction levels, including a computer architecture, an OS, or runtime libraries. A computing platform is the stage. A platform can be seen both as a constraint on the software development process, in that different platforms provide different functionality and restrictions. For example, an OS may be a platform that abstracts the underlying differences in hardware and provides a generic command for saving files or accessing the network. Platforms may include: Hardware alone, in the case of small embedded systems. Embedded systems can access hardware directly, without an OS. A browser in the case of web-based software; the browser itself runs on a hardware+OS 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 an application-specific scripting language, such as an Excel macro. This can be extended to writing fully-fledged applications with the Microsoft Office suite as a platform. Software frameworks. Cloud computing and Platform as a Service. Extending the idea of a software framework, these allow application developers to build software out of components that are hosted not by the developer, but by the provider, with internet communication linking them together; the social networking sites Twitter and Facebook are considered development platforms. A virtual machine such as the Java virtual machine or. NET CLR. Applications are compiled into a format similar to machine code, known as bytecode, executed by the VM. A virtualized version of a complete system, including virtualized hardware, OS, storage; these allow, for instance, a typical Windows program to run on. 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 beneath it. For instance, a Java program has to be written to use the Java virtual machine and associated libraries as a platform but does not have to be adapted to run for the Windows, Linux or Macintosh OS platforms. However, the JVM, the layer beneath the application, does have to be built separately for each OS. AmigaOS, AmigaOS 4 FreeBSD, NetBSD, OpenBSD IBM i Linux Microsoft Windows OpenVMS Classic Mac OS macOS OS/2 Solaris Tru64 UNIX VM QNX z/OS Android Bada BlackBerry OS Firefox OS iOS Embedded Linux Palm OS Symbian Tizen WebOS LuneOS Windows Mobile Windows Phone Binary Runtime Environment for Wireless Cocoa Cocoa Touch Common Language Infrastructure Mono. NET Framework Silverlight Flash AIR GNU Java platform Java ME Java SE Java EE JavaFX JavaFX Mobile LiveCode Microsoft XNA Mozilla Prism, XUL and XULRunner Open Web Platform Oracle Database Qt SAP NetWeaver Shockwave Smartface Universal Windows Platform Windows Runtime Vexi Ordered from more common types to less common types: Commodity computing platforms Wintel, that is, Intel x86 or compatible personal computer hardware with Windows operating system Macintosh, custom Apple Inc. hardware and Classic Mac OS and macOS operating systems 68k-based PowerPC-based, now migrated to x86 ARM architecture based mobile devices iPhone smartphones and iPad tablet computers devices running iOS from Apple Gumstix or Raspberry Pi full function miniature computers with Linux Newton devices running the Newton OS from Apple x86 with Unix-like systems such as Linux or BSD variants CP/M computers based on the S-100 bus, maybe the earliest microcomputer platform Video game consoles, any variety 3DO Interactive Multiplayer, licensed to manufacturers Apple Pippin, a multimedia player platform for video game console development RISC processor based machines running Unix variants SPARC architecture computers running Solaris or illumos operating systems DEC Alpha cluster running OpenVMS or Tru64 UNIX Midrange computers with their custom operating systems, such as IBM OS/400 Mainframe computers with their custom operating systems, such as IBM z/OS Supercomputer architectures Cross-platform Platform virtualization Third platform Ryan Sarver: What is a platform
Hibernation is a state of inactivity and metabolic depression in endotherms. Hibernation refers to a season of heterothermy characterized by low body temperature, slow breathing and heart rate, low metabolic rate, it is most observed during the winter months. Although traditionally reserved for "deep" hibernators such as rodents, the term has been redefined to include animals such as bears and is now applied based on active metabolic suppression rather than any absolute decline in body temperature. Many experts believe that the processes of daily torpor and hibernation form a continuum and utilize similar mechanisms; the equivalent during the summer months is aestivation. Associated with low temperatures, hibernation functions to conserve energy when sufficient food is unavailable. To achieve this energy saving, an endothermic animal decreases its metabolic rate and thereby its body temperature. Hibernation may last days, weeks, or months depending on the species, ambient temperature, time of year, the individual's body condition.
Before entering hibernation, animals need to store enough energy to last through the duration of their dormant period as long as the entire winter. Larger species become hyperphagic, eating a large amount of food and storing the energy in fat deposits. In many small species, food caching replaces becoming fat; some species of mammals hibernate while gestating young, which are born either while the mother hibernates or shortly afterwards. For example, female polar bears go into hibernation during the cold winter months in order to give birth to their offspring; the pregnant mothers increase their body mass prior to hibernation, this increase is further reflected in the weight of the offspring. The fat accumulation enables them to provide a sufficiently warm and nurturing environment for their newborns. During hibernation, they subsequently lose 15–27% of their pre-hibernation weight by using their stored fats for energy. True hibernation is restricted to endotherms. Still, many ectothermic animals undergo periods of dormancy which are sometimes confused with hibernation.
Some reptile species are said to brumate, but possible similarities between brumation and hibernation are not established. Many insects, such as the wasp Polistes exclamans, exhibit periods of dormancy which have been referred to as hibernation, despite their ectothermy. Obligate hibernators are animals that spontaneously, annually, enter hibernation regardless of ambient temperature and access to food. Obligate hibernators include many species of ground squirrels, other rodents, mouse lemurs, European hedgehogs and other insectivores and marsupials These species undergo what has been traditionally called "hibernation": a physiological state wherein the body temperature drops to near ambient temperature, heart and respiration rates slow drastically; the typical winter season for obligate hibernators is characterized by periods of torpor interrupted by periodic, euthermic arousals, during which body temperatures and heart rates are restored to more typical levels. The cause and purpose of these arousals is still not clear.
One favored hypothesis is that hibernators build a "sleep debt" during hibernation, so must warm up to sleep. This has been supported by evidence in the Arctic ground squirrel. Other theories postulate that brief periods of high body temperature during hibernation allow the animal to restore its available energy sources or to initiate an immune response. Hibernating Arctic ground squirrels may exhibit abdominal temperatures as low as −2.9 °C, maintaining sub-zero abdominal temperatures for more than three weeks at a time, although the temperatures at the head and neck remain at 0 °C or above. There was a question of whether or not bears hibernate since they experience only a modest decline in body temperature compared with the much larger decreases seen in other hibernators. Many researchers thought that their deep sleep was not comparable with true, deep hibernation, but recent research has refuted this theory in captive black bears. Unlike obligate hibernators, facultative hibernators only enter hibernation when either cold-stressed, food-deprived, or both.
A good example of the differences between these two types of hibernation can be seen in prairie dogs: the white-tailed prairie dog is an obligate hibernator and the related black-tailed prairie dog is a facultative hibernator. While hibernation has long been studied in rodents, namely ground squirrels, no primate or tropical mammal was known to hibernate until the discovery of hibernation in the fat-tailed dwarf lemur of Madagascar, which hibernates in tree holes for seven months of the year. Malagasy winter temperatures sometimes rise to over 30 °C, so hibernation is not an adaptation to low ambient temperatures; the hibernation of this lemur is dependent on the thermal behaviour of its tree hole: if the hole is poorly insulated, the lemur's body temperature fluctuates passively following the ambient temperature. Dausmann found that hypometabolism in hibernating animals is not coupled with low body temperature. Hibernating bears are able to recycle their proteins and urine, allowing them both to stop urinating for months and to avoid muscl