Editing OS/2 (section)

==Development{{anchor|Development history}}==
{{more citations needed section|date=April 2012}}

===1985–1990: Joint IBM–Microsoft development===

{{multiple image
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| image1            = OS-2 1.x logo glowing.svg
| caption1          = Logo of OS/2 1.x
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| caption2          = OS/2 1.0 featured a text-mode interface similar to MS-DOS.
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The development of OS/2 began when IBM and Microsoft signed the "Joint Development Agreement" in August 1985.<ref>{{Cite web|title=Joint Development Agreement Between International Business Machines Corporation And Microsoft Corporation|url=https://www.tech-insider.org/personal-computers/research/acrobat/871126.pdf|url-status=live|archive-url=https://web.archive.org/web/20210815044103/https://www.tech-insider.org/personal-computers/research/acrobat/871126.pdf|archive-date=August 15, 2021|access-date=August 15, 2021|website=Tech Insider}}</ref><ref name="JointAgreementPR">{{cite press release| title=Microsoft Operating System/2 With Windows Presentation Manager Provides Foundation for Next Generation of Personal Computer Industry|author=Michal Necasek| work=The History of OS/2| date=April 2, 1987| archive-date=April 10, 2010| access-date=March 25, 2013| url=http://pages.prodigy.net/michaln/history/pr/87apr_m3592.html|archive-url=https://web.archive.org/web/20100410013835/http://pages.prodigy.net/michaln/history/pr/87apr_m3592.html |url-status=dead}}</ref> It was code-named "CP/DOS" and it took two years for the first product to be delivered.

====OS/2 1.0 (1987){{anchor|1.0}}====
OS/2's release was long delayed. It was widely believed that all IBM programmers used [[assembly language]], and a rumor said that the delay was because they had to learn [[C (language)|C]].<ref name="vose198807">{{Cite magazine |last=Vose |first=G. Michael |date=July 1988 |title=Reader's Guide to OS/2 |url=https://archive.org/details/byte-1988-07_202104/page/51/mode/1up?view=theater |access-date=2025-04-12 |department=Book Reviews |magazine=[[Byte (magazine)|Byte]] |pages=51-54}}</ref> OS/2 1.0 was announced in April 1987 and released in December. The original release only ran in [[text mode]], and a GUI was introduced with OS/2 1.1 about a year later. OS/2 features an [[Application programming interface|API]] for controlling the [[display device|video display]] (VIO) and handling [[computer keyboard|keyboard]] and mouse events so that programmers writing for [[protected mode]] need not call the [[BIOS]] or access hardware directly. Other development tools included a subset of the video and keyboard APIs as linkable libraries so that family mode programs are able to run under MS-DOS,{{citation needed|date=April 2019}} and, in the OS/2 Extended Edition v1.0, a database engine called Database Manager or DBM (this was related to [[DB2]], and should not be confused with the [[DBM (computing)|DBM]] family of database engines for Unix and [[Unix-like]] operating systems).<ref>{{cite web|url=http://users.informatik.uni-halle.de/~brass/zert08/c1_produ.pdf|title=DBA Certification Course (Summer 2008) Chapter 1: DB2 Products and Tools|website=Users.informatik.uni-halle.de|access-date=2 April 2019}}</ref> A task-switcher named Program Selector was available through the Ctrl-Esc [[hotkey]] combination, allowing the user to select among multitasked text-mode sessions (or screen groups; each can run multiple programs).<ref>{{cite web|title=OS/2 1.0|author=Michal Necasek|work=The History of OS/2|date=2001-07-16|url=http://pages.prodigy.net/michaln/history/os210/index.html|url-status=dead|archive-url=https://web.archive.org/web/20100811211529/http://pages.prodigy.net/michaln/history/os210/index.html|archive-date=2010-08-11}}</ref>

Communications and database-oriented extensions were delivered in 1988, as part of OS/2 1.0 Extended Edition: [[Systems Network Architecture|SNA]], [[X.25]]/[[Advanced Program-to-Program Communication|APPC]]/LU 6.2, [[LAN Manager]], [[Query Management Facility|Query Manager]], SQL.

[[File:Os2-1.1-desktop.png|thumb|right|OS/2 1.1 was the first version to feature the Presentation Manager GUI.]]

====OS/2 1.1 (1988){{anchor|1.1}}====
The promised user interface, [[Presentation Manager]], was introduced with OS/2 1.1 in October 1988.<ref name="Both1996">{{cite web|title=A Short History of OS/2|author=David Both|work=DataBook for OS/2 Warp|date=May 2, 2012|orig-year=originally published December 19, 1996|url=http://www.databook.bz/?page_id=223|access-date=April 9, 2013|archive-url=https://web.archive.org/web/20130218111519/http://www.databook.bz/?page_id=223|archive-date=February 18, 2013|url-status=dead}}</ref> It had a similar user interface to [[Windows 2.1x|Windows 2.1]], which was released in May of that year. (The interface was replaced in versions 1.2 and 1.3 by a look closer in appearance to [[Windows 3.0]].)

The Extended Edition of 1.1, sold only through IBM sales channels, introduced distributed database support to IBM database systems and SNA communications support to IBM mainframe networks.

====OS/2 1.2 (1989){{anchor|1.2|1.21}}====
In 1989, Version 1.2 introduced Installable Filesystems and, notably, the [[High Performance File System|HPFS]] [[File system|filesystem]]. HPFS provided a number of improvements over the older [[File Allocation Table|FAT]] file system, including long filenames and a form of [[Fork (file system)|alternate data streams]] called [[Extended Attributes]].<ref>{{cite web|title=HPFS|author=H. Gilbert|work=Das Boot|publisher=PC Lube and Tune|year=1995|url=http://www.yale.edu/pclt/BOOT/HPFS.htm|url-status=dead|archive-url=https://web.archive.org/web/20060714193222/http://www.yale.edu/pclt/BOOT/HPFS.htm|archive-date=2006-07-14|access-date=2006-06-09}}</ref> In addition, extended attributes were also added to the FAT file system.<ref>{{cite web|title=Implementation of extended attributes on the FAT file system|author =Bob Eager|work=Tavi Systems|date=28 October 2000|url=http://www.tavi.co.uk/os2pages/eadata.html}}</ref>

[[Image:MS-OS2-v1.0-diskettes.jpg|left|thumb|Installation Disk A of Microsoft OS/2 1.3 (3½-inch floppy disk)]]

The Extended Edition of 1.2 introduced [[Internet protocol suite|TCP/IP]] and [[Ethernet]] support.

OS/2- and Windows-related books of the late 1980s from both Microsoft's [[Gordon Letwin]] and his IBM counterpart [[Ed Iacobucci]] acknowledged the existence of both systems and promoted OS/2 as the system of the future.<ref>{{cite book|last=Iacobucci|first=Ed|author-link=Ed Iacobucci|author2=foreword by [[Bill Gates]]|title=OS/2 Programmer's Guide|year=1988| publisher=[[McGraw-Hill Osborne Media]]|chapter=Foreword|isbn=0-07-881300-X|quote=I believe OS/2 is destined to be the most important operating system, and possibly program, of all time. As the successor to DOS, which has over 10,000,000 systems in use, it creates incredible opportunities for everyone involved with PCs.}}</ref>{{r|vose198807}}

===1990: Breakup===
====OS/2 1.3 (1990){{anchor|1.3}}====
[[File:MSOS2.png|thumb|Logo of Microsoft's OS/2 until the breakup]]
The collaboration between IBM and Microsoft unravelled in 1990, between the releases of [[Windows 3.0]] and OS/2 1.3. During this time, Windows 3.0 became a tremendous success, selling millions of copies in its first year.<ref>{{cite web|url=https://www.thoughtco.com/unusual-history-of-microsoft-windows-1992140|title=The Unusual History of Microsoft Windows|last=Bellis|first=Mary|work=ThoughtCo.|publisher=Dotdash}}</ref> Much of its success was because Windows 3.0 (along with MS-DOS) was bundled with most new computers.<ref>{{cite web | title=Windows History (1985–1994) | author=Thomas Hormby | work=osviews.com | date=25 May 2005 | url=http://www.osopinion.com/modules.php?op=modload&name=News&file=article&sid=4484 | url-status=dead | archive-url=https://web.archive.org/web/20060312130710/http://www.osopinion.com/modules.php?op=modload&name=News&file=article&sid=4484 | archive-date=March 12, 2006 | access-date=April 9, 2013 }}</ref> OS/2, on the other hand, was available only as an additional stand-alone software package. In addition, OS/2 lacked [[device driver]]s for many common devices such as printers, particularly non-IBM hardware.<ref>{{cite web|title=OS/2 1.1 and 1.2: The Early Years|author=Michal Necasek|work=The History of OS/2|date=2001-10-29|url=http://pages.prodigy.net/michaln/history/os211/index.html|url-status=dead|archive-url=https://web.archive.org/web/20060613211334/http://pages.prodigy.net/michaln/history/os211/index.html|archive-date=2006-06-13}}</ref> Windows, on the other hand, supported a much larger variety of hardware. The increasing popularity of Windows prompted Microsoft to shift its development focus from cooperating on OS/2 with IBM to building its own business based on Windows.<ref>{{cite web|title=Windows Server 2003: The Road To Gold|author=Paul Thurrott|work=winsupersite.com|date=24 January 2003|url=http://www.winsupersite.com/reviews/winserver2k3_gold1.asp|url-status=dead|archive-url=https://web.archive.org/web/20100604082534/http://www.winsupersite.com/reviews/winserver2k3_gold1.asp|archive-date=4 June 2010}}</ref>

Several technical and practical reasons contributed to this breakup. The two companies had significant differences in culture and vision. Microsoft favored the open hardware system approach that contributed to its success on the PC. IBM sought to use OS/2 to drive sales of its own hardware, and urged Microsoft to drop features, such as [[Computer font|fonts]], that IBM's hardware did not support. Microsoft programmers also became frustrated with IBM's bureaucracy and its use of [[Source lines of code|lines of code]] to measure [[programmer productivity]].<ref>{{cite book|last1=Gates|first1=Bill|author-link=Bill Gates|first2=Nathan|last2=Myhrvold|author-link2=Nathan Myhrvold|first3=Peter|last3=Rinearson|author-link3=Peter Rinearson|title=The Road Ahead|isbn=0-670-77289-5|url=https://archive.org/details/roadahead00gate|date=1996-10-08}}</ref> IBM developers complained about the terseness and lack of [[comment (computer programming)|comments]] in Microsoft's code, while Microsoft developers complained that IBM's code was [[code bloat|bloated]].<ref>{{cite book|author=Michael Lee Vasu|author2=Debra W. Stewart|author3=G. David Garson|title=Organizational behavior and public management|page=268|isbn=978-0-8247-0135-2|url=https://books.google.com/books?id=bu2JkldQjXcC&q=IBM+measure+lines+of+code&pg=PA267|date=1998-03-03|publisher=Taylor & Francis }}</ref>

The two products have significant differences in API. OS/2 was announced when [[Windows 2.0]] was near completion, and the [[Windows API]] already defined. However, IBM requested that this API be significantly changed for OS/2.<ref>{{cite web|title="What's happening to OS/2," a Usenet post by Gordon Letwin from August 1995, the point of view of a Microsoft employee|author=Gordon Letwin|work=Google Groups|url=http://groups.google.com/group/comp.os.ms-windows.misc/msg/d710490b745d5e5e|access-date=2007-10-18|archive-url=https://web.archive.org/web/20070923013722/http://groups.google.com/group/comp.os.ms-windows.misc/msg/d710490b745d5e5e|archive-date=2007-09-23|url-status=dead}}</ref> Therefore, issues surrounding application compatibility appeared immediately. OS/2 designers hoped for source code conversion tools, allowing complete migration of Windows application source code to OS/2 at some point. However, OS/2 1.x did not gain enough momentum to allow vendors to avoid developing for both OS/2 and Windows in parallel.

[[File:OS2-1.3-desktop.png|thumb|right|OS/2 1.3 was the final 16-bit only version of OS/2, and the last to be sold by Microsoft.]]

OS/2 1.x targets the [[Intel 80286]] processor and DOS fundamentally does not. IBM insisted on supporting the 80286 processor, with its 16-bit [[x86 memory segmentation|segmented memory]] mode, because of commitments made to customers who had purchased many 80286-based PS/2s as a result of IBM's promises surrounding OS/2.<ref name="BillGatesInterviewSmithsonian">{{cite interview |last=Gates |first=Bill |subject-link= Bill Gates |interviewer= David Allison |url= http://americanhistory.si.edu/comphist/gates.htm |title= Bill Gates Interview |type= transcript of a Video History interview |work= Computer History Collection |publisher= National Museum of American History, Smithsonian Institution |access-date= April 10, 2013 }}</ref> Until release 2.0 in April 1992, OS/2 ran in 16-bit [[protected mode]] and therefore could not benefit from the [[Intel 80386]]'s much simpler [[32-bit computing|32-bit]] [[flat memory model]] and [[virtual 8086 mode]] features. This was especially painful in providing support for DOS applications. While, in 1988, [[Windows 2.1x|Windows/386 2.1]] could run several [[cooperative multitasking|cooperatively multitasked]] DOS applications, including [[expanded memory]] (EMS) emulation, OS/2 1.3, released in 1991, was still limited to one {{nowrap|640 kB}} "DOS box".

Given these issues, Microsoft started to work in parallel on a version of Windows which was more future-oriented and more portable. The hiring of [[Dave Cutler]], former [[OpenVMS|VAX/VMS]] architect, in 1988 created an immediate competition with the OS/2 team, as Cutler did not think much of the OS/2 technology and wanted to build on his work on the [[DEC MICA|MICA]] project at [[Digital Equipment Corporation|Digital]] rather than creating a "DOS plus". His [[Windows NT|NT OS/2]] was a completely new architecture.<ref>{{cite book|author=Microsoft|title=Inside Out, Microsoft—In Our Own Words|year=2000|publisher=Warner Business Books|isbn=0-446-52739-4}}</ref>

IBM grew concerned about the delays in development of OS/2 2.0. Initially, the companies agreed that IBM would take over maintenance of OS/2 1.0 and development of OS/2 2.0, while Microsoft would continue development of OS/2 3.0. In the end, Microsoft decided to recast NT OS/2 3.0 as Windows NT, leaving all future OS/2 development to IBM. From a business perspective, it was logical to concentrate on a consumer line of operating systems based on DOS and Windows, and to prepare a new high-end system in such a way as to keep good compatibility with existing Windows applications. While it waited for this new high-end system to develop, Microsoft would still receive licensing money from Xenix and OS/2 sales. Windows NT's OS/2 heritage can be seen in its initial support for the [[HPFS filesystem]], text mode OS/2 1.x applications, and OS/2 LAN Manager network support. Some early NT materials even included OS/2 copyright notices embedded in the software.{{Citation needed|date=April 2010}}
One example of NT OS/2 1.x support is in the WIN2K resource kit. Windows NT could also support OS/2 1.x [[Presentation Manager]] and AVIO applications with the addition of the Windows NT Add-On Subsystem for Presentation Manager.<ref name="CompatibilityofOS2basedAppsandAPIs">{{cite web | title=Compatibility of OS/2-based Applications and APIs | author=Microsoft | work=Microsoft TechNet | date=11 September 2008 | url=https://technet.microsoft.com/library/Cc939070 | publisher=Microsoft | access-date=April 9, 2013 }}</ref>

===1990–1996: Post-breakup{{anchor|32-bit era}}===
====OS/2 2.0 (1992){{anchor|2.0}}====
[[Image:Os2-2.0-wps.png|right|thumb|OS/2 2.0 was the first 32-bit release of OS/2, and the first to feature the Workplace Shell.]]

OS/2 2.0 was released in April 1992. At the time, the suggested retail price was {{US$|195}}, while Windows retailed for {{US$|long=no|150}}.<ref name="Baltimore_Sun">{{cite news |last=Corr |first=O. Casey |title=GIANT-KILLER? Microsoft mounts challenge to IBM |format=Not available in the EU; check the archive URL instead |newspaper=The Baltimore Sun |date=1992-04-06 |url= https://www.baltimoresun.com/news/bs-xpm-1992-04-06-1992097044-story.html |archive-url= https://web.archive.org/web/20200305171806/https://www.baltimoresun.com/news/bs-xpm-1992-04-06-1992097044-story.html |archive-date=2020-03-05}}</ref>

OS/2 2.0 provided a 32-bit API for native programs, though the OS itself still contained some 16-bit code and drivers. It also included a new OOUI (object-oriented user interface) called the [[Workplace Shell]]. This was a fully object-oriented interface that was a significant departure from the previous GUI. Rather than merely providing an environment for program windows (such as the Program Manager), the Workplace Shell provided an environment in which the user could manage programs, files and devices by manipulating objects on the screen. With the Workplace Shell, everything in the system is an "object" to be manipulated.

OS/2 2.0 was touted by IBM as "a better DOS than DOS and a better Windows than Windows".<ref>{{cite news |title=Killer Apps: For Apple's Windows Strategy to Work, It Must Replace Microsoft Office and Buy Adobe Systems |author=Robert X. Cringely |work=pbs.org |date=27 April 2006 |url= https://www.pbs.org/cringely/pulpit/2006/pulpit_20060427_000894.html}}</ref> It managed this by including the fully-licensed MS-DOS 5.0, which had been patched and improved upon. For the first time, OS/2 was able to run more than one DOS application at a time. This was so effective that it allowed OS/2 to run a modified copy of Windows 3.0, itself a [[DOS extender]], including Windows 3.0 applications.

Because of the limitations of the [[Intel 80286]] processor, OS/2 1.x could run only one DOS program at a time, and did this in a way that allowed the DOS program to have total control over the computer. A problem in DOS mode could crash the entire computer. In contrast, OS/2 2.0 could leverage the [[virtual 8086 mode]] of the [[Intel 80386]] processor to create a much safer [[virtual machine]] in which to run DOS programs. This included an extensive set of configuration options to optimize the performance and capabilities given to each DOS program. Any real-mode operating system (such as 8086 [[Xenix]]) could also be made to run using OS/2's virtual machine capabilities, subject to certain direct hardware access limitations.

[[Image:OS2 2.0 upgrade box.png|right|thumb|The OS/2 2.0 upgrade box]]

Like most 32-bit environments, OS/2 could not run protected-mode DOS programs using the older [[VCPI]] interface, unlike the Standard mode of Windows 3.1; it only supported programs written according to [[DOS Protected Mode Interface|DPMI]]. (Microsoft discouraged the use of VCPI under Windows 3.1, however, due to performance degradation.)<ref>{{cite web|title=Windows 3.1 Standard Mode and the VCPI |author=Microsoft |work=support.microsoft.com |date=6 November 1999 |url=http://support.microsoft.com/kb/82298 |url-status=dead |archive-url=https://web.archive.org/web/20130309020041/http://support.microsoft.com/kb/82298 |archive-date=March 9, 2013 }}</ref>

Unlike Windows NT, OS/2 always allowed DOS programs the possibility of masking real hardware interrupts, so any DOS program could [[deadlock (computer science)|deadlock]] the machine in this way. OS/2 could, however, use a hardware [[non-maskable interrupt|watchdog]] on selected machines (notably IBM machines) to break out of such a deadlock. Later, release 3.0 leveraged the enhancements of newer [[i486|Intel 80486]] and [[Pentium (original)|Intel Pentium]] processors&mdash;the [[Virtual Interrupt Flag]] (VIF), which was part of the [[Virtual Mode Extensions]] (VME)&mdash;to solve this problem.

To accommodate those who wanted to have multiple operating systems on their machine, Boot Manager was introduced that allowed for the creation of separate partitions on the boot drive which could be used to install different versions of DOS, Windows and OS/2 and give the user a choice of which partition to boot from.<ref>{{Cite web |date=2014-08-05 |title=Using OS/2 Boot Manager to install multiple operating systems on a single hard file - IBM PC/IBM IntelliStation |url=https://www.ibm.com/support/pages/using-os2-boot-manager-install-multiple-operating-systems-single-hard-file-ibm-pcibm-intellistation |access-date=2025-05-05 |website=www.ibm.com |language=en}}</ref>
{{Further|VME (CONFIG.SYS directive)}}

====OS/2 2.1 (1993){{anchor|2.1}}====
OS/2 2.1 was released in 1993. This version of OS/2 achieved compatibility with Windows 3.0 (and later Windows 3.1) by adapting Windows user-mode code components to run inside a [[virtual DOS machine]] (VDM). Originally, a nearly complete version of Windows code was included with OS/2 itself: Windows 3.0 in OS/2 2.0, and Windows 3.1 in OS/2 2.1. Later, IBM developed versions of OS/2 that would use whatever Windows version the user had installed previously, patching it on the fly, and sparing the cost of an additional Windows license.<ref>{{cite web |title=Team OS/2 Frequently Asked Questions |author=Christian Alice Scarborough |date=15 September 1998 |url=http://www.faqs.org/faqs/Team-OS2-FAQ/}}</ref> It could either run full-screen, using its own set of video drivers, or "seamlessly," where Windows programs would appear directly on the OS/2 desktop. The process containing Windows was given fairly extensive access to hardware, especially video, and the result was that switching between a full-screen WinOS/2 session and the Workplace Shell could occasionally cause issues.<ref>{{cite web |title=OS/2 Games Setting Archive |work=Game Zero magazine |date=6 March 1995 |url=http://www.gamezero.com/team-0/pc_games/os2.html |access-date=9 June 2006 |archive-url=https://web.archive.org/web/20060614014635/http://www.gamezero.com/team-0/pc_games/os2.html |archive-date=14 June 2006 |url-status=dead }}</ref>

Because OS/2 only runs the user-mode system components of Windows, it is incompatible with Windows device drivers ([[VxD]]s) and applications that require them.

Multiple Windows applications run by default in a single Windows session – multitasking cooperatively and without memory protection – just as they would under native Windows 3.x. However, to achieve true isolation between Windows 3.x programs, OS/2 can also run multiple copies of Windows in parallel, with each copy residing in a separate VDM. The user can then optionally place each program either in its own Windows session – with preemptive multitasking and full memory protection ''between'' sessions, though not ''within'' them – or allow some applications to run together cooperatively in a shared Windows session while isolating other applications in one or more separate Windows sessions. At the cost of additional hardware resources, this approach can protect each program in any given Windows session (and each instance of Windows itself) from every other program running in any ''separate'' Windows session (though not from other programs running in the same Windows session).<ref name="pcw199407_os2">{{ cite magazine | title=OS/2 for Windows | magazine=Personal Computer World | date=July 1994 | last1=Bidmead | first1=Chris | pages=251–252 }}</ref>

Whether Windows applications are running in full-screen or windowed mode, and in one Windows session or several, it is possible to use [[Dynamic Data Exchange|DDE]] between OS/2 and Windows applications, and [[Object Linking and Embedding|OLE]] between Windows applications only.<ref>{{cite web |title=OS/2 Warp Frequently Asked Questions List |author=Timothy F. Sipples |date=20 February 1995 |url=https://www.mit.edu/activities/os2/faq/os2faq0103.html}}</ref>

IBM's '''OS/2 for Windows''' product (codename Ferengi), also known as "OS/2, Special Edition", was interpreted as a deliberate strategy "of cashing in on the pervasive success of the Microsoft platform" but risked confusing consumers with the notion that the product was a mere accessory or utility running on Windows such as [[Norton Commander|Norton Desktop for Windows]] when, in fact, it was "a complete, modern, multi-tasking, pre-emptive operating system", itself hosting Windows instead of running on it. Available on CD-ROM or 18 floppy disks, the product documentation reportedly suggested Windows as a prerequisite for installing the product, also being confined to its original FAT partition, whereas the product apparently supported the later installation of Windows running from an HPFS partition, particularly beneficial for users of larger hard drives. Windows compatibility, relying on patching specific memory locations, was reportedly broken by the release of Windows 3.11, prompting accusations of arbitrary changes to Windows in order to perpetrate "a deliberate act of Microsoft sabotage" against IBM's product.<ref name="pcw199407_os2"/>

====OS/2 Warp 3 (1994){{anchor|OS/2 Warp|3.0|3.0J|The "Warp" years}}====
{{multiple image
| align             = right
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| image1            = OS-2 Warp Version 3 wordmark.svg
| caption1          = Wordmark of OS/2 Warp 3.0
| image2            = os2-warp-3.png
| caption2          = OS/2 Warp Connect 3.0, showing the Windows 3.1 [[Program Manager]], [[QBASIC]] in a DOS window, and the LaunchPad (bottom center)
}}

Released in 1994, OS/2 version 3.0 was labelled as '''OS/2 Warp''' to highlight the new performance benefits, and generally to freshen the product image. "Warp" had originally been the internal IBM name for the release: IBM claimed that it had used ''[[Star Trek]]'' terms as internal names for prior OS/2 releases, and that this one seemed appropriate for external use as well. At the launch of OS/2 Warp in 1994, [[Patrick Stewart]] was to be the [[Master of Ceremonies]]; however [[Kate Mulgrew]]<ref name="KateMulgrewBioIMDB">{{cite web | title=Biography for Kate Mulgrew | website=Internet Movie Database | url=https://www.imdb.com/name/nm0000550/bio | quote=In 1996, was contracted by IBM to help promote the latest release of OS/2 Warp, version 4 (previously codenamed Merlin), due to associations with Star Trek.}}</ref> of the then-upcoming series ''[[Star Trek: Voyager]]'' substituted for him at the last minute.<ref name="InSearchofStupidityWeb">{{cite web |url=http://www.insearchofstupidity.com/ch6.htm |title=In Search of Stupidity, Excerpts from Chapter 6 |website=Insearchofstupidity.com |access-date=April 9, 2013 |archive-url=https://web.archive.org/web/20130127185712/http://www.insearchofstupidity.com/ch6.htm |archive-date=January 27, 2013 |url-status=dead }}</ref><ref name="InSearchofStupidityBook">{{cite book | title=In Search of Stupidity: Over 20 Years of High-tech Marketing Disasters | first=Merrill R. | last=Chapman | date=2006 | publisher=Apress | location=Berkeley, California | edition=2nd | isbn= 9781590597217 | oclc=71275572 | medium=Paperback | quote=They rented a hall in New York City and invited hundreds to see Patrick Stewart, the then current captain of the Starship Enterprise to help roll out the product in a gala event. (Stewart was a no-show.|page=108)}}</ref>

OS/2 Warp offers a host of benefits over OS/2 2.1, notably broader hardware support, greater multimedia capabilities, [[Internet]]-compatible networking, and it includes a basic office application suite known as [[IBM Works]]. It was released in two versions: the less expensive "Red Spine" and the more expensive "Blue Spine" (named for the color of their boxes). "Red Spine" was designed to support [[Microsoft Windows]] applications by utilizing any existing installation of Windows on the computer's hard drive. "Blue Spine" includes Windows support in its own installation, and so can support Windows applications without a Windows installation. As most computers were sold with Microsoft Windows pre-installed and the price was less, "Red Spine" was the more popular product.<ref name="ars201311">{{cite web |last1=Reimer |first1=Jeremy |title=Half an operating system: The triumph and tragedy of OS/2 |url=https://arstechnica.com/information-technology/2019/11/half-an-operating-system-the-triumph-and-tragedy-of-os2/ |website=[[Ars Technica]] |access-date=4 April 2023 |archive-url=https://web.archive.org/web/20230326084822/https://arstechnica.com/information-technology/2019/11/half-an-operating-system-the-triumph-and-tragedy-of-os2/ |archive-date=26 March 2023 |date=November 2013 |url-status=live}}</ref> OS/2 Warp Connect—which has full LAN client support built-in—followed in mid-1995. Warp Connect was nicknamed "Grape".<ref name=Both1996 />

In OS/2 2.0, most performance-sensitive subsystems, including the graphics (Gre) and multimedia (MMPM/2) systems, were updated to 32-bit code in a fixpack, and included as part of OS/2 2.1. Warp 3 brought about a fully 32-bit windowing system, while Warp 4 introduced the object-oriented 32-bit GRADD display driver model.

====Workplace OS (1995) {{Anchor|Workplace OS|WorkplaceOS}}====
{{Main|Workplace OS}}
In 1991, IBM started development on an intended replacement for OS/2 called [[Workplace OS]]. This was an entirely new product, brand new code, that borrowed only a few sections of code from both the existing OS/2 and AIX products. It used an entirely new microkernel code base, intended (eventually) to host several of IBM's operating systems (including OS/2) as microkernel "personalities". It also included major new architectural features including a system registry, JFS, support for UNIX graphics libraries, and a new driver model.<ref name="WorkplaceMicrokernelandOS">{{cite tech report | url=http://www.cs.ucr.edu/~brett/PAPERS/SPE97/REVISED/techreport.ps | archive-url=https://web.archive.org/web/20070824050732/http://www.cs.ucr.edu/~brett/PAPERS/SPE97/REVISED/techreport.ps | archive-date=August 24, 2007 | access-date=March 25, 2013 | title=Workplace Microkernel and OS: A Case Study | first1=Brett D | last1=Fleisch | first2=Mark | last2=Allan | date=September 23, 1997 | publisher=John Wiley & Sons, Ltd. |format=PostScript }}</ref>

Workplace OS was developed solely for [[PowerPC|POWER platforms]], and IBM intended to market a full line of PowerPCs in an effort to take over the market from [[Intel]]. A mission was formed to create prototypes of these machines and they were disclosed to several corporate customers, all of whom raised issues with the idea of dropping Intel.

Advanced plans for the new code base would eventually include replacement of the [[OS/400]] operating system by Workplace OS, as well as a microkernel product that would have been used in industries such as telecommunications and set-top television receivers.

A partially functional pre-alpha version of Workplace OS was demonstrated at Comdex, where a bemused [[Bill Gates]] stopped by the booth. The second and last time it would be shown in public was at an OS/2 user group in [[Phoenix, Arizona]]; the pre-alpha code refused to boot.

It was released in 1995. But with $990 million being spent per year on development of this as well as Workplace OS, and no possible profit or widespread adoption, the end of the entire Workplace OS and OS/2 product line was near.

====OS/2 Warp 4 (1996){{anchor|Warp 4|4.0|4.5}}====
[[Image:Firefox 3.5.4 on OS2 Warp4.png|thumb|left|Firefox 3.5.4 for OS/2 Warp 4]]
{{multiple image
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| image1            = OS-2 Warp 4 wordmark.svg
| caption1          = Wordmark of OS/2 Warp 4
| image2            = OS-2 W4.png
| caption2          = OS/2 Warp 4 desktop after installation
}}

In 1996, Warp 4 added [[Java (programming language)|Java]] and [[speech recognition]] software.<ref>{{cite web |last1=Edwards |first1=Ben J. |title=OS/2's Last Stand: IBM OS/2 Warp 4 Turns 25 |url=https://www.howtogeek.com/755650/os2s-last-stand-ibm-os2-warp-4-turns-25/ |website=www.howtogeek.com |date=26 September 2021 |publisher=HowToGeek |access-date=26 September 2021}}</ref> IBM also released server editions of Warp 3 and Warp 4 which bundled IBM's LAN Server product directly into the operating system installation. A personal version of [[IBM Notes|Lotus Notes]] was also included, with a number of template databases for contact management, brainstorming, and so forth. The UK-distributed free demo [[CD-ROM]] of OS/2 Warp essentially contained the entire OS and was easily, even accidentally, [[Software cracking|cracked]]{{clarify|date=November 2012}}, meaning that even people who liked it did not have to buy it. This was seen as a backdoor tactic to increase the number of OS/2 users, in the belief that this would increase sales and demand for third-party applications, and thus strengthen OS/2's desktop numbers.{{Citation needed|date=April 2010}} This suggestion was bolstered by the fact that this demo version had replaced another which was not so easily cracked, but which had been released with trial versions of various applications.{{Citation needed|date=April 2010}} In 2000, the July edition of ''[[Australian Personal Computer]]'' magazine bundled software CD-ROMs, included a full version of Warp 4 that required no activation and was essentially a free release. Special versions of OS/2 2.11 and Warp 4 also included [[symmetric multiprocessing]] (SMP) support.

OS/2 sales were largely concentrated in networked computing used by corporate professionals; however, by the early 1990s, it was overtaken by Microsoft Windows NT. While OS/2 was arguably technically superior to Microsoft [[Windows 95]], OS/2 failed to develop much penetration in the consumer and stand-alone desktop PC segments; there were reports that it could not be installed properly on IBM's own [[IBM Aptiva|Aptiva]] series of home PCs.<ref name="OS2NoLongerHomeatHome">{{cite news| url=https://www.nytimes.com/1995/08/08/science/personal-computers-os-2-no-longer-at-home-at-home.html?src=pm | work=The New York Times | first=Peter H. | last=Lewis | title=PERSONAL COMPUTERS; OS/2 No Longer at Home at Home | date=8 August 1995}}</ref> Microsoft made an offer in 1994 where IBM would receive the same terms as [[Compaq]] (the largest PC manufacturer at the time) for a license of Windows 95, if IBM ended development of OS/2 completely. IBM refused and instead went with an "IBM First" strategy of promoting OS/2 Warp and disparaging Windows, as IBM aimed to drive sales of its own software as well as hardware. By 1995, Windows 95 negotiations between IBM and Microsoft, which were already difficult, stalled when IBM purchased [[Lotus SmartSuite]], which would have directly competed with [[Microsoft Office]]. As a result of the dispute, IBM signed the license agreement 15 minutes before Microsoft's Windows 95 launch event, which was later than their competitors and this badly hurt sales of IBM PCs. IBM officials later conceded that OS/2 would not have been a viable operating system to keep them in the PC business.<ref name="MSUrgedIBMtoYankSmartsuite">{{cite journal | title=MS/DoJ: Microsoft urged IBM to yank Smart Suite | first=Elizabeth | last=Wasserman | date=June 8, 1999 | journal=PC World | url=http://www.pcworld.idg.com.au/article/105777/ms_doj_microsoft_urged_ibm_yank_smart_suite/ | access-date=April 10, 2013 | archive-date=January 16, 2014 | archive-url=https://web.archive.org/web/20140116121938/http://www.pcworld.idg.com.au/article/105777/ms_doj_microsoft_urged_ibm_yank_smart_suite/ | url-status=dead }}</ref><ref>{{cite web|url=http://www.albion.com/microsoft/findings-23.html |title=C. The Similar Experiences of Other Firms in Dealing with Microsoft |website=Albion.com |access-date=2013-03-20}}</ref>

===1996–2001: Downsizing{{anchor|Downsizing}}===
{{unreferenced section|date=March 2013}}
A project was launched internally by IBM to evaluate the looming competitive situation with Microsoft Windows 95. Primary concerns included the major code quality issues in the existing OS/2 product (resulting in over 20 service packs, each requiring more diskettes than the original installation), and the ineffective and heavily matrixed development organization in Boca Raton (where the consultants reported that "basically, everybody reports to everybody") and Austin.

That study, tightly classified as "Registered Confidential" and printed only in numbered copies, identified untenable weaknesses and failures across the board in the Personal Systems Division as well as across IBM as a whole. This resulted in a decision being made at a level above the Division to cut over 95% of the overall budget for the entire product line, end all new development (including Workplace OS), eliminate the Boca Raton development lab, end all sales and marketing efforts of the product, and lay off over 1,300 development individuals (as well as sales and support personnel). $990 million had been spent in the last full year. Warp 4 became the last distributed version of OS/2.

===2001–2006: Discontinuation and end-of-life{{anchor|Fading out}}===

Although a small and dedicated community remains faithful to OS/2,<ref name="OS2World">{{cite web|url=http://www.os2world.com/forum/ |title=OS2 World Community Forum – Index |website=Os2world.com |access-date=2013-03-20}}</ref> OS/2 failed to catch on in the mass market and is little used outside certain niches where IBM traditionally had a stronghold. For example, many bank installations, especially [[automated teller machine]]s, run OS/2 with a customized user interface; French [[SNCF]] national railways used OS/2 1.x in thousands of ticket selling machines.{{Citation needed|date=June 2011}} Telecom companies such as [[Nortel]] used OS/2 in some voicemail systems. Also, OS/2 was used for the host PC used to control the [[Public Radio Satellite System|Satellite Operations Support System]] equipment installed at [[NPR]] member stations from 1994 to 2007, and used to receive the network's programming via satellite.{{Citation needed|date=June 2011}}

Although IBM began indicating shortly after the release of Warp 4 that OS/2 would eventually be withdrawn, the company did not end support until December 31, 2006,<ref name="EOL">{{cite web|title=End of Standard Support|author=IBM|url=http://www-306.ibm.com/software/os/warp/index.html|access-date=2006-08-08|archive-url=https://web.archive.org/web/20060909074608/http://www-306.ibm.com/software/os/warp/index.html|archive-date=2006-09-09|url-status=dead}}</ref> with sales of OS/2 stopping on December 23, 2005. The latest IBM OS/2 Warp version is 4.52, which was released for both desktop and server systems in December 2001.

IBM is still delivering defect support for a fee.<ref name="EOL" /><ref name="EOL2">{{cite web | title=OS/2 Warp: Warranties and Licenses | publisher=IBM | url=http://www-01.ibm.com/software/os/warp-withdrawal/services.html | access-date=April 9, 2013 }}</ref> IBM urges customers to migrate their often highly complex applications to [[Electronic business|e-business]] technologies such as Java in a platform-neutral manner. Once application migration is completed, IBM recommends migration to a different operating system, suggesting [[Linux]] as an alternative.<ref name="MigrationStation">{{cite web | title=Migration Station | website=[[IBM]] | url=http://www.ibm.com/developerworks/ondemand/migrate/linux.html#6 | url-status=dead | archive-url=https://web.archive.org/web/20100513182513/http://www.ibm.com/developerworks/ondemand/migrate/linux.html#6 | archive-date=May 13, 2010 | access-date=April 9, 2013 }}</ref><ref name="LinuxMigrate2">{{cite web |url=http://www.redbooks.ibm.com/abstracts/sg246631.html?Open |title=IBM Redbooks &#124; OS/2 Server Transition |website=Redbooks.ibm.com |date=2003-10-06 |access-date=2013-03-20 |url-status=dead |archive-url=https://web.archive.org/web/20140201181645/http://www.redbooks.ibm.com/abstracts/sg246631.html?Open |archive-date=2014-02-01 }}</ref><ref name="JavaMigrate">{{cite web |url=http://ecomstation.ru/projects/reseller/download/cat97_gen.pdf |title=3346/GEN/K (1–32) (Page 1) |access-date=2013-03-20 |archive-url=https://web.archive.org/web/20120318100423/http://ecomstation.ru/projects/reseller/download/cat97_gen.pdf |archive-date=2012-03-18 |url-status=dead }}</ref>

===2001–present: Third-party development{{anchor|Third-party development}}===

{{Main|eComStation|ArcaOS}}

[[File:ArcaOS_5.0_Screenshot.png|thumb|ArcaOS is the most recent OS/2-based operating system developed outside of IBM.|260x260px]]

After IBM discontinued development of OS/2, various third parties approached IBM to take over future development of the operating system. The OS/2 software vendor [[Stardock]] made such a proposal to IBM in 1999, but it was not followed through by the company.<ref name="dan">Dan Casey: [http://www.man.lodz.pl/LISTY/OS2/1999/09/0319.html OS/2 Voice Press Release] {{Webarchive|url=https://web.archive.org/web/20111008092813/http://www.man.lodz.pl/LISTY/OS2/1999/09/0319.html |date=2011-10-08 }} - 21 Sept 1999.</ref> Serenity Systems succeeded in negotiating an agreement with IBM, and began reselling OS/2 as eComStation in 2001.<ref>{{cite web|url=https://www.os2world.com/wiki/index.php/OS/2,_ArcaOS_and_eComStation_Versions_and_Languages|access-date=2020-08-24|title=OS/2, ArcaOS and eComStation Versions and Languages}}</ref> eComStation is now sold by XEU.com, the most recent version (2.1) was released in 2011.<ref name="v21release">{{cite web |url=http://www.ecomstation.com/news.phtml?action=fullnews&id=3698&title=eComStation%202.1%20GA%20available |title=News :: eComStation 2.1 GA available |website=eComStation.com |access-date=2013-03-20 |archive-date=2013-05-12 |archive-url=https://web.archive.org/web/20130512053520/http://www.ecomstation.com/news.phtml?action=fullnews&id=3698&title=eComStation%202.1%20GA%20available |url-status=dead }}</ref> In 2015, Arca Noae, LLC announced that they had secured an agreement with IBM to resell OS/2.<ref name="Blue Lion 1st Article" /> They released the first version of their OS/2-based operating system in 2017 as ArcaOS.<ref name="arcaos-release" /> As of 2023, there have been multiple releases of ArcaOS, and it remains under active development.<ref>{{cite web|url=https://www.arcanoae.com/roadmaps/arcaos/|access-date=2023-10-21|title=Roadmap: ArcaOS|website=arcanoae.com|date=2023-09-02}}</ref>

====Petitions for open source====
Many people hoped that IBM would release OS/2 or a significant part of it as [[open-source software|open source]]. Petitions were held in 2005 and 2007, but IBM refused them, citing legal and technical reasons.<ref>{{cite web| title=Slashdot: IBM Won't Open-Source OS/2| date=22 January 2008 |url=http://slashdot.org/article.pl?sid=08/01/22/0258213 }}</ref> It is unlikely that the entire OS will be open at any point in the future because it contains third-party code to which IBM does not have copyright, and much of this code is from Microsoft. IBM also once engaged in a technology transfer with [[Commodore International|Commodore]], licensing [[Amiga]] technology for OS/2 2.0 and above, in exchange for the [[Rexx|REXX]] scripting language.<ref name=HistoryOS2BBS>{{cite web|title=OS/2 Warp History|url=http://www.os2bbs.com/os2news/OS2Warp.html|url-status=dead|archive-url=https://web.archive.org/web/20130127122310/http://www.os2bbs.com/os2news/OS2Warp.html|archive-date=January 27, 2013|access-date=April 9, 2013}}</ref>{{Unreliable source?|date=October 2021}} This means that OS/2 may have some code that was not written by IBM, which can therefore prevent the OS from being re-announced as open-sourced in the future.<ref>{{cite web|title=IBM OS/2 Warp History|date=2004-06-24|url=http://www.os2world.com/content/view/15847/1/|access-date=2008-09-09|archive-url=https://web.archive.org/web/20080919095144/http://www.os2world.com/content/view/15847/1/|archive-date=2008-09-19|url-status=dead}}</ref>{{Failed verification|date=June 2011}}<ref>The Art of Unix Programming p. 66 {{ISBN|0-13-142901-9}}, {{ISBN|978-0-13-142901-7}}</ref> On the other hand, [[IBM]] donated [[Object REXX]] for Windows and OS/2 to the ''Open Object REXX'' project maintained by the ''REXX Language Association'' on [[SourceForge]].<ref>{{cite web |url=http://www.oorexx.org/faq/ |title=Open Object REXX FAQ |access-date=2011-07-05}}</ref>

There was a petition, arranged by OS2World, to open parts of the OS. Open source operating systems such as [[Linux]] have already profited from OS/2 indirectly through IBM's release of the improved [[JFS (file system)|JFS]] [[file system]], which was ported from the OS/2 code base. As IBM didn't release the source of the OS/2 JFS driver, developers ported the Linux driver back to eComStation and added the functionality to boot from a JFS partition. This new JFS driver has been integrated into eComStation v2.0, and later into ArcaOS 5.0.