The R4200 is a microprocessor designed by MIPS Technologies, Inc. (MTI) that implemented the MIPS III instruction set architecture (ISA). It was also known as the VRX during development. The microprocessor was licensed to NEC , and the company fabricated and marketed it as the VR4200. The first VR4200, an 80 MHz part, was introduced in 1993. A faster 100 MHz part became available in 1994.
77-492: The R4200 was at least in part intended for use in low-power Windows NT computers such as personal computers and laptops, reportedly offering "Pentium processor performance at a tenth of the price", having initially aimed to deliver twice the performance of a 66 MHz Intel 486DX2 processor. Reported SPECint benchmark results put the microprocessor's integer performance at around 85% of a P5-variant Pentium microprocessor, with floating-point performance being about half that of
154-432: A dedicated x64 edition ) has x64 editions. The first version of Windows NT to support ARM64 devices with Qualcomm processors was Windows 10, version 1709 . This is a full version of Windows, rather than the cut-down Windows RT . The minimum hardware specification required to run each release of the professional workstation version of Windows NT has been fairly slow-moving until the 6.0 (Vista) release, which requires
231-513: A taskbar and Start menu ), which originally appeared in Windows 95 . The first release was given version number 3.1 to match the contemporary 16-bit Windows; magazines of that era claimed the number was also used to make that version seem more reliable than a ".0" release. Also the Novell IPX protocol was apparently licensed only to 3.1 versions of Windows software. The NT version number
308-476: A trade secret . Software can be made available with fewer restrictions on licensing or source-code access; software that satisfies certain conditions of freedom and openness is known as " free " or " open-source ." Since license agreements do not override applicable copyright law or contract law , provisions in conflict with applicable law are not enforceable. Some software is specifically licensed and not sold, in order to avoid limitations of copyright such as
385-507: A "mixed source" model including both free and non-free software in the same distribution. Most if not all so-called proprietary UNIX distributions are mixed source software, bundling open-source components like BIND , Sendmail , X Window System , DHCP , and others along with a purely proprietary kernel and system utilities. Some free software packages are also simultaneously available under proprietary terms. Examples include MySQL , Sendmail and ssh. The original copyright holders for
462-410: A 16 kB instruction cache and an 8 kB data cache. Both caches are direct-mapped . The instruction cache has a 32-byte line size, whereas the data cache has 16-byte line size. The data cache uses the write-back write protocol. The R4200 has a 32-entry translation lookaside buffer (TLB) for data, and a 4-entry TLB for instructions. A 33-bit physical address is supported. The system bus
539-455: A 64-bit kernel and 64-bit memory addressing. Windows NT is a group or family of products — like Windows is a group or family. Windows NT is a sub-grouping of Windows. The first version of Windows NT, 3.1 , was produced for workstation and server computers. It was commercially focused — and intended to complement consumer versions of Windows that were based on MS-DOS (including Windows 1.0 through Windows 3.1x ). In 1996, Windows NT 4.0
616-523: A February 21, 1997, internal Microsoft memo drafted for Bill Gates : Early versions of the iPhone SDK were covered by a non-disclosure agreement . The agreement forbade independent developers from discussing the content of the interfaces. Apple discontinued the NDA in October 2008. Any dependency on the future versions and upgrades for a proprietary software package can create vendor lock-in , entrenching
693-467: A Government Security Program (GSP) to allow governments to view source code and Microsoft security documentation, of which the Chinese government was an early participant. The program is part of Microsoft's broader Shared Source Initiative which provides source code access for some products. The Reference Source License (Ms-RSL) and Limited Public License (Ms-LPL) are proprietary software licenses where
770-945: A MIPS implementation produced significant royalties for MTI, sales for NEC, and made MIPS the highest volume mixed 32/64-bit RISC ISA in 1997. NEC produced two other derivatives of the R4300 for the general embedded market, the VR4305 and VR4310, announced on 20 January 1998. The VR4310 was available at 100, 133 or 167 MHz. It was manufactured in a 250 nm process and packaged in a 120-pin PQFP. Windows NT 24H2 (10.0.26100.2454) (November 21, 2024 ; 2 days ago ( 2024-11-21 ) ) [±] 23H2 (10.0.22635.4515) (November 22, 2024 ; 1 day ago ( 2024-11-22 ) ) [±] 24H2 (10.0.26120.2415) (November 22, 2024 ; 1 day ago ( 2024-11-22 ) ) [±] Windows NT
847-401: A TCP/IP stack derived at first from a STREAMS -based stack from Spider Systems , then later rewritten in-house). Windows NT 3.1 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 and switches from 16-bit to 32-bit addressing in pages. Windows NT 3.1 featured a core kernel providing
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#1732786990462924-401: A copy can decide whether, and how much, to charge for a copy or related services. Proprietary software that comes for no cost is called freeware . Proponents of commercial proprietary software argue that requiring users to pay for software as a product increases funding or time available for the research and development of software. For example, Microsoft says that per-copy fees maximize
1001-402: A cut-down 32-bit system bus for reduced cost. The chip had an area of 45 mm and was fabricated in a 350 nm process. By employing multiplexed address and data lines, it could be packaged in a low-cost 120-pin PQFP. It uses a 3.3 V power supply and dissipates 1.5 W running at 40 MHz (80 MHz internally), 1.8 W at 100 MHz and 2.2 W at 133 MHz. The R4300i
1078-471: A layered design architecture that consists of two main components, user mode and kernel mode . Programs and subsystems in user mode are limited in terms of what system resources they have access to, while the kernel mode has unrestricted access to the system memory and external devices. Kernel mode in Windows NT has full access to the hardware and system resources of the computer. The Windows NT kernel
1155-564: A license for the Internet forum software vBulletin can modify the source for their own site but cannot redistribute it. This is true for many web applications, which must be in source code form when being run by a web server. The source code is covered by a non-disclosure agreement or a license that allows, for example, study and modification, but not redistribution. The text-based email client Pine and certain implementations of Secure Shell are distributed with proprietary licenses that make
1232-509: A maximum of 2 W at 80 MHz. In comparison to the Pentium, SPECint ratings had the Pentium at 64.5 and the R4200 at 55. SPECfp ratings had the Pentium at 56 versus the R4200 at 30. The R4300i is a derivative of the R4200 designed by MTI for embedded applications announced on 17 April 1995. It differs from the R4200 by featuring an improved integer multiplier with a lower latency and
1309-420: A minimum of 15 GB of free disk space, a tenfold increase in free disk space alone over the previous version, and the 2021 10.0 (11) release which excludes most systems built before 2018. Proprietary software Proprietary software is software that grants its creator, publisher, or other rightsholder or rightsholder partner a legal monopoly by modern copyright and intellectual property law to exclude
1386-560: A monopoly position. Proprietary software may also have licensing terms that limit the usage of that software to a specific set of hardware. Apple has such a licensing model for macOS , an operating system which is limited to Apple hardware, both by licensing and various design decisions. This licensing model has been affirmed by the United States Court of Appeals for the Ninth Circuit . Proprietary software which
1463-601: A portable operating system, compatible with OS/2 and POSIX and supporting multiprocessing , in October 1988. When development started in November 1989, Windows NT was to be known as OS/2 3.0, the third version of the operating system developed jointly by Microsoft and IBM . To ensure portability, initial development was targeted at the Intel i860 XR RISC processor , switching to the MIPS R3000 in late 1989, and then
1540-520: A revision of Windows NT, even though the Windows NT name itself has not been used in many other Windows releases since Windows NT 4.0 in 1996. Windows NT provides many more features than other Windows releases, among them being support for multiprocessing , multi-user systems , a "pure" 32-bit kernel with 32-bit memory addressing, support for instruction sets other than x86 , and many other system services such as Active Directory and more. Newer versions of Windows NT support 64-bit computing , with
1617-481: A single user or computer. In some cases, software features are restricted during or after the trial period, a practice sometimes called crippleware . Proprietary software often stores some of its data in file formats that are incompatible with other software, and may also communicate using protocols which are incompatible. Such formats and protocols may be restricted as trade secrets or subject to patents . A proprietary application programming interface (API)
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#17327869904621694-462: A software package may be ended to force users to upgrade and pay for newer versions ( planned obsolescence ). Sometimes another vendor or a software's community themselves can provide support for the software, or the users can migrate to either competing systems with longer support life cycles or to FOSS -based systems. Some proprietary software is released by their owner at end-of-life as open-source or source available software, often to prevent
1771-475: A stripped-down version of the Windows operating system. Windows 11 is the first non-server version of Windows NT that does not support 32-bit platforms. The 64-bit versions of Windows NT were originally intended to run on Itanium and DEC Alpha ; the latter was used internally at Microsoft during early development of 64-bit Windows. This continued for some time after Microsoft publicly announced that it
1848-444: A system API, running in supervisor mode (ring 0 in x86; referred to in Windows NT as "kernel mode" on all platforms), and a set of user-space environments with their own APIs which included the new Win32 environment, an OS/2 1.3 text-mode environment and a POSIX environment. The full preemptive multitasking kernel could interrupt running tasks to schedule other tasks, without relying on user programs to voluntarily give up control of
1925-425: A technical measure, such as product activation , a product key or serial number, a hardware key , or copy protection . Vendors may also distribute versions that remove particular features, or versions which allow only certain fields of endeavor, such as non-commercial, educational, or non-profit use. Use restrictions vary by license: Vendors typically distribute proprietary software in compiled form, usually
2002-555: A very small amount written in assembly language . C is mostly used for the kernel code while C++ is mostly used for user-mode code. Assembly language is avoided where possible because it would impede portability . The following are the releases of Windows based on the Windows NT technology. Windows NT 3.1 to 3.51 incorporated the Program Manager and File Manager from the Windows 3.1x series. Windows NT 4.0 onwards replaced those programs with Windows Explorer (including
2079-406: A work of free software, even copyleft free software, can use dual-licensing to allow themselves or others to redistribute proprietary versions. Non-copyleft free software (i.e. software distributed under a permissive free software license or released to the public domain) allows anyone to make proprietary redistributions. Free software that depends on proprietary software is considered "trapped" by
2156-510: Is 64 bits wide and operates at half the internal clock frequency. The R4200 contained 1.3 million transistors and had an area of 81 mm. NEC fabricated the R4200 in a 600 nm CMOS process with three levels of interconnect. It was packaged in a 179-pin ceramic pin grid array that was compatible with the R4x00PC and R4600 , or a 208-pin plastic quad flat pack (PQFP). It used a 3.3 V power supply, dissipating 1.8 W typically and
2233-525: Is a hybrid kernel ; the architecture comprises a simple kernel , hardware abstraction layer (HAL), drivers, and a range of services (collectively named Executive ), which all exist in kernel mode. The booting process of Windows NT begins with NTLDR in versions before Vista and the Windows Boot Manager in Vista and later. The boot loader is responsible for accessing the file system on
2310-473: Is a proprietary graphical operating system produced by Microsoft as part of its Windows product line, the first version of which, Windows NT 3.1 , was released on July 27, 1993. Originally made for the workstation , office, and server markets, the Windows NT line was made available to consumers with the release of Windows XP in 2001. The underlying technology of Windows NT continues to exist to this day with incremental changes and improvements, with
2387-484: Is a software library interface "specific to one device or, more likely to a number of devices within a particular manufacturer's product range." The motivation for using a proprietary API can be vendor lock-in or because standard APIs do not support the device's functionality. The European Commission , in its March 24, 2004, decision on Microsoft's business practices, quotes, in paragraph 463, Microsoft general manager for C++ development Aaron Contorer as stating in
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2464-463: Is achieved on IA-32 via an integrated DOS Virtual Machine – although this feature is not available on other architectures. NT has supported per-object (file, function, and role) access control lists allowing a rich set of security permissions to be applied to systems and services. NT has also supported Windows network protocols, inheriting the previous OS/2 LAN Manager networking, as well as TCP/IP networking (for which Microsoft used to implement
2541-489: Is no longer marketed, supported or sold by its owner is called abandonware , the digital form of orphaned works . If the proprietor of a software package should cease to exist, or decide to cease or limit production or support for a proprietary software package, recipients and users of the package may have no recourse if problems are found with the software. Proprietors can fail to improve and support software because of business problems. Support for older or existing versions of
2618-466: Is not now generally used for marketing purposes, but is still used internally, and said to reflect the degree of changes to the core of the operating system. However, for application compatibility reasons, Microsoft kept the major version number as 6 in releases following Vista, but changed it later to 10 in Windows 10. The build number is an internal identifier used by Microsoft's developers and beta testers. Starting with Windows 8.1 , Microsoft changed
2695-436: Is not synonymous with commercial software , although the two terms are sometimes used synonymously in articles about free software. Proprietary software can be distributed at no cost or for a fee, and free software can be distributed at no cost or for a fee. The difference is that whether proprietary software can be distributed, and what the fee would be, is at the proprietor's discretion. With free software, anyone who has
2772-400: Is required for another party to use the software. In the case of proprietary software with source code available, the vendor may also prohibit customers from distributing their modifications to the source code. Shareware is closed-source software whose owner encourages redistribution at no cost, but which the user sometimes must pay to use after a trial period. The fee usually allows use by
2849-448: Is the use of the integer datapath for performing arithmetic operations on the mantissa portion of a floating point number. A separate datapath was used for the exponent. This scheme reduced cost by reducing the number of transistors , the size of the chip, and power consumption. It also impacted floating point performance negatively, but the R4200's intended applications did not require high floating point performance. The R4200 has
2926-596: The Intel i386 in 1990. Microsoft also continued parallel development of the DOS-based and less resource -demanding Windows environment, resulting in the release of Windows 3.0 in May 1990. Windows 3.0 was eventually so successful that Microsoft decided to change the primary application programming interface for the still unreleased NT OS/2 (as it was then known) from an extended OS/2 API to an extended Windows API . This decision caused tension between Microsoft and IBM and
3003-752: The PowerPC processor in 1995, specifically PReP -compliant systems such as the IBM ThinkPad Power Series laptops and Motorola PowerStack series; but despite meetings between Michael Spindler and Bill Gates, not on the Power Macintosh as the PReP compliant Power Macintosh project failed to ship. Intergraph Corporation ported Windows NT to its Clipper architecture and later announced an intention to port Windows NT 3.51 to Sun Microsystems ' SPARC architecture, in conjunction with
3080-590: The Windows 8 -derived Windows RT on October 26, 2012, and the use of Windows NT, rather than Windows CE, in Windows Phone 8 . The original Xbox and Xbox 360 run a custom operating system based upon a heavily modified version of Windows 2000 , an approach that Microsoft engineer Don Box called "fork and run". It exports APIs similar to those found in Microsoft Windows , such as Direct3D . The Xbox One and Xbox Series X/S consoles use
3157-649: The Windows Preinstallation Environment , which is a lightweight version of Windows NT made for deployment of the operating system. Since Windows Vista, the Windows installation files, as well as the preinstallation environment used to install Windows, are stored in the Windows Imaging Format . It is possible to use the Deployment Image Servicing and Management (DISM) tool to install Windows from
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3234-425: The first-sale doctrine . The owner of proprietary software exercises certain exclusive rights over the software. The owner can restrict the use, inspection of source code, modification of source code, and redistribution. Vendors typically limit the number of computers on which software can be used, and prohibit the user from installing the software on extra computers. Restricted use is sometimes enforced through
3311-468: The machine language understood by the computer's central processing unit . They typically retain the source code , or human-readable version of the software, often written in a higher level programming language . This scheme is often referred to as closed source. While most proprietary software is distributed without the source code, some vendors distribute the source code or otherwise make it available to customers. For example, users who have purchased
3388-511: The Alpha NT 5 (Windows 2000) release had reached RC1 status. On January 5, 2011, Microsoft announced that the next major version of the Windows NT family will include support for the ARM architecture . Microsoft demonstrated a preliminary version of Windows (version 6.2.7867) running on an ARM-based computer at the 2011 Consumer Electronics Show . This eventually led to the commercial release of
3465-554: The CPU, as in Windows 3.1 Windows applications (although MS-DOS applications were preemptively multitasked in Windows starting with Windows/386 ). Notably, in Windows NT 3.x, several I/O driver subsystems, such as video and printing, were user-mode subsystems. In Windows NT 4.0, the video, server, and printer spooler subsystems were moved into kernel mode. Windows NT's first GUI was strongly influenced by (and programmatically compatible with) that from Windows 3.1; Windows NT 4.0's interface
3542-476: The DEC Alpha. Windows NT and VMS memory management , processes , and scheduling are very similar. Windows NT's process management differs by implementing threading , which DEC did not implement until VMS 7.0 in 1995. Like VMS, Windows NT's kernel mode code distinguishes between the "kernel", whose primary purpose is to implement processor- and architecture-dependent functions, and the "executive". This
3619-625: The Free Software Foundation. This includes software written only for Microsoft Windows, or software that could only run on Java , before it became free software. Most of the software is covered by copyright which, along with contract law , patents , and trade secrets , provides legal basis for its owner to establish exclusive rights. A software vendor delineates the specific terms of use in an end-user license agreement (EULA). The user may agree to this contract in writing, interactively on screen ( clickwrap ), or by opening
3696-601: The Pentium. Expected to be used in Nintendo's "new machine due in 1995", the R4300i variant was used in the widely popular Nintendo 64 video game console and SNK’s Hyper Neo Geo 64 arcade board. The R4200 ultimately did not see any use in personal computers and was repositioned as an embedded microprocessor that competed with the R4600 . The R4200 is a scalar design with a five-stage classic RISC pipeline . A notable feature
3773-589: The Version API Helper functions' behavior. If an application is not manifested for Windows 8.1 or later, the API will always return version 6.2, which is the version number of Windows 8 . This is because the manifest feature was introduced with Windows 8.1, to replace GetVersion and related functions. In order to prevent Intel x86 -specific code from slipping into the operating system, due to developers being used to developing on x86 chips, Windows NT 3.1
3850-662: The Windows NT driver model, and is incompatible with older driver frameworks. 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. Windows Vista added native support for the Windows Driver Foundation , which is also available for Windows XP , Windows Server 2003 and to an extent, Windows 2000 . Microsoft decided to create
3927-556: The boot drive, starting the kernel , and loading boot-time device drivers into memory. Once all the boot and system drivers have been loaded, the kernel starts the Session Manager Subsystem . This process launches winlogon , which allows the user to login. Once the user is logged in File Explorer is started, loading the graphical user interface of Windows NT. Windows NT is written in C and C++ , with
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#17327869904624004-416: The box containing the software ( shrink wrap licensing ). License agreements are usually not negotiable . Software patents grant exclusive rights to algorithms, software features, or other patentable subject matter , with coverage varying by jurisdiction. Vendors sometimes grant patent rights to the user in the license agreement. The source code for a piece of proprietary software is routinely handled as
4081-452: The collaboration ultimately fell apart. IBM continued OS/2 development alone while Microsoft continued work on the newly renamed Windows NT. Though neither operating system would immediately be as popular as Microsoft's MS-DOS or Windows products, Windows NT would eventually be far more successful than OS/2. Microsoft hired a group of developers from Digital Equipment Corporation led by Dave Cutler to build Windows NT, and many elements of
4158-450: The command line and skip the GUI installer. 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 originally 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
4235-660: The company's planned introduction of UltraSPARC models in 1995, but neither version was sold to the public as a retail product. Only two of the Windows NT 4.0 variants (IA-32 and Alpha) have a full set of service packs available. All of the other ports done by third parties (Motorola, Intergraph, etc.) have few, if any, publicly available updates. Windows NT 4.0 was the last major release to support Alpha, MIPS, or PowerPC, though development of Windows 2000 for Alpha continued until August 1999, when Compaq stopped support for Windows NT on that architecture; and then three days later Microsoft also canceled their AlphaNT program, even though
4312-401: The design reflect earlier DEC experience with Cutler's VMS , VAXELN and RSX-11 , but also an unreleased object-based operating system developed by Cutler at Digital codenamed MICA . The team was joined by selected members of the disbanded OS/2 team, including Moshe Dunie . Although NT was not an exact clone of Cutler's previous operating systems, DEC engineers almost immediately noticed
4389-521: The executive. Routines from each are directly accessible, as for example from kernel-mode device drivers. API sets in the Windows NT family are implemented as subsystems atop the publicly undocumented "native" API ; this allowed the late adoption of the Windows API (into the Win32 subsystem). Windows NT was one of the earliest operating systems to use UCS-2 and UTF-16 internally. Windows NT uses
4466-544: The internal similarities. Parts of VAX/VMS Internals and Data Structures , published by Digital Press , accurately describe Windows NT internals using VMS terms. Furthermore, parts of the NT codebase's directory structure and filenames matched that of the MICA codebase. Instead of a lawsuit, Microsoft agreed to pay DEC $ 65–100 million, help market VMS, train Digital personnel on Windows NT, and continue Windows NT support for
4543-447: The late 1960s, computers—especially large and expensive mainframe computers , machines in specially air-conditioned computer rooms—were usually leased to customers rather than sold . Service and all software available were usually supplied by manufacturers without separate charge until 1969. Computer vendors usually provided the source code for installed software to customers. Customers who developed software often made it available to
4620-432: The latest version of Windows based on Windows NT being Windows 11 in 2021. The name "Windows NT" originally denoted the major technological advancements that it had introduced to the Windows product line, including eliminating the 16-bit memory access limitations of earlier Windows releases such as Windows 3.1 and the Windows 9x series. Each Windows release built on this technology is considered to be based on, if not
4697-619: The legal status of software copyright , especially for object code , was not clear until the 1983 appeals court ruling in Apple Computer, Inc. v. Franklin Computer Corp . According to Brewster Kahle the legal characteristic of software changed also due to the U.S. Copyright Act of 1976 . Starting in February 1983 IBM adopted an " object-code -only" model for a growing list of their software and stopped shipping much of
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#17327869904624774-571: The names of releases from Windows 2000 and later, though Microsoft described that product as being "Built on NT Technology". "NT" was a trademark of Northern Telecom (later Nortel ), which Microsoft was forced to acknowledge on the product packaging. One of the main purposes of NT is hardware and software portability. Various versions of NT family operating systems have been released for a variety of processor architectures, initially IA-32 , MIPS , and DEC Alpha , with PowerPC , Itanium , x86-64 and ARM supported in later releases. An initial idea
4851-414: The original target processor—the Intel i860 , code-named N10 ("N-Ten"). A 1991 video featuring Bill Gates and Microsoft products specifically says that "Windows NT stands for 'New Technology'". Seven year later in 1998, during a question-and-answer (Q&A) session, he then revealed that the letters were previously expanded to such but no longer carry any specific meaning. The letters were dropped from
4928-712: The public without charge. Closed source means computer programs whose source code is not published except to licensees. It is available to be modified only by the organization that developed it and those licensed to use the software. In 1969, IBM, which had antitrust lawsuits pending against it, led an industry change by starting to charge separately for mainframe software and services, by unbundling hardware and software. Bill Gates ' " Open Letter to Hobbyists " in 1976 decried computer hobbyists' rampant copyright infringement of software, particularly Microsoft's Altair BASIC interpreter, and asserted that their unauthorized use hindered his ability to produce quality software. But
5005-549: The recipient from freely sharing the software or modifying it, and—in some cases, as is the case with some patent-encumbered and EULA -bound software—from making use of the software on their own, thereby restricting their freedoms. Proprietary software is a subset of non-free software , a term defined in contrast to free and open-source software ; non-commercial licenses such as CC BY-NC are not deemed proprietary, but are non-free. Proprietary software may either be closed-source software or source-available software . Until
5082-561: The software from becoming unsupported and unavailable abandonware . 3D Realms and id Software are famous for the practice of releasing closed source software into the open source . Some of those kinds are free-of-charge downloads ( freeware ), some are still commercially sold (e.g. Arx Fatalis ). More examples of formerly closed-source software in the List of commercial software with available source code and List of commercial video games with available source code . Proprietary software
5159-484: The software. This is particularly common with certain programming languages . For example, the bytecode for programs written in Java can be easily decompiled to somewhat usable code, and the source code for programs written in scripting languages such as PHP or JavaScript is available at run time . Proprietary software vendors can prohibit the users from sharing the software with others. Another unique license
5236-402: The source code available. Some licenses for proprietary software allow distributing changes to the source code, but only to others licensed for the product, and some of those modifications are eventually picked up by the vendor. Some governments fear that proprietary software may include defects or malicious features which would compromise sensitive information. In 2003 Microsoft established
5313-476: The source code is made available . Governments have also been accused of adding such malware to software themselves. According to documents released by Edward Snowden , the NSA has used covert partnerships with software companies to make commercial encryption software exploitable to eavesdropping, or to insert backdoors . Software vendors sometimes use obfuscated code to impede users who would reverse engineer
5390-606: The source code, even to licensees. In 1983, binary software became copyrightable in the United States as well by the Apple vs. Franklin law decision, before which only source code was copyrightable. Additionally, the growing availability of millions of computers based on the same microprocessor architecture created for the first time an unfragmented and big enough market for binary distributed software. Software distributions considered as proprietary may in fact incorporate
5467-423: Was cancelling plans to ship 64-bit Windows for Alpha. Because of this, Alpha versions of Windows NT are 32-bit only. While Windows 2000 only supports Intel IA-32 (32-bit), Windows XP, Server 2003, Server 2008 and Server 2008 R2 each have one edition dedicated to Itanium-based systems. In comparison with Itanium, Microsoft adopted x64 on a greater scale: every version of Windows since Windows XP (which has
5544-459: Was designed as a modified microkernel , as the Windows NT kernel was influenced by the Mach microkernel developed by Richard Rashid at Carnegie Mellon University, but does not meet all of the criteria of a pure microkernel. Both the kernel and the executive are linked together into the single loaded module ntoskrnl.exe ; from outside this module, there is little distinction between the kernel and
5621-523: Was initially developed using non-x86 development systems and then ported to the x86 architecture. This work was initially based on the Intel i860 -based Dazzle system and, later, the MIPS R4000-based Jazz platform. Both systems were designed internally at Microsoft. Windows NT 3.1 was released for Intel x86 PC compatible and PC-98 platforms, and for DEC Alpha and ARC -compliant MIPS platforms. Windows NT 3.51 added support for
5698-554: Was licensed to NEC and Toshiba , and was marketed by those companies as the VR4300 or TX4300, respectively. Both companies offered 100 and 133 MHz versions. A derivative of the VR4300 was developed by NEC for the Nintendo 64 game console, clocked at 93.75 MHz and labeled NUS-CPU. Although development boards for the Nintendo 64 used stock NEC VR4300 CPUs, the final CPU has been found to be not pin-compatible. This singular use of
5775-419: Was redesigned to match that of the brand-new Windows 95 , moving from the Program Manager to the Windows shell design. NTFS , a journaled, secure file system, is a major feature of NT. Windows NT also allows for other installable file systems; NT can also be installed on FAT file systems, and versions 3.1, 3.5, and 3.51 could be installed HPFS file systems. Windows NT introduced its own driver model,
5852-502: Was released, including the new shell from Windows 95 . Eventually, Microsoft incorporated the Windows NT technology into the Windows product line for personal computing and deprecated the Windows 9x family. Starting with Windows 2000 , "NT" was removed from the product name yet is still in several low-level places in the system — including for a while as part of the product version. Versions of Windows NT are installed using Windows Setup , which, starting with Windows Vista , uses
5929-443: Was to have a common code base with a custom Hardware Abstraction Layer (HAL) for each platform. However, support for MIPS, Alpha, and PowerPC was later dropped in Windows 2000 . Broad software compatibility was initially 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 and Windows 16-bit compatibility
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