OS/2

OS/2 is a <a href="/facts/Proprietary_software/9zcskxYL">proprietary</a> computer <a href="/facts/Operating_system/8XTuvMh2">operating system</a> for <a href="/facts/X86/Kypq5fgu">x86</a> and <a href="/facts/PowerPC/DqmM9y50">PowerPC</a> based <a href="/facts/Personal_computers/koaYfNce">personal computers</a>. It was created and initially developed jointly by <a href="/facts/IBM/QszA7nwd">IBM</a> and <a href="/facts/Microsoft/nGIDDXdx">Microsoft</a>, under the leadership of IBM software designer <a href="/facts/Ed_Iacobucci/fT69GNfj">Ed Iacobucci</a>, intended as a replacement for <a href="/facts/DOS/sWwDXNmX">DOS</a>. The first version was released in 1987. A feud between the two companies beginning in 1990 led to Microsoft’s leaving development solely to IBM, which continued development on its own. OS/2 Warp 4 in 1996 was the last major upgrade, after which IBM slowly halted the product as it failed to compete against Microsoft's <a href="/facts/Microsoft_Windows/bwhAhuSL">Windows</a>; updated versions of OS/2 were released by IBM until 2001.
The name stands for "Operating System/2", because it was introduced as part of the same generation change release as IBM's "<a href="/facts/IBM_Personal_System%2f2/G299srDC">Personal System/2</a> (PS/2)" line of second-generation PCs. OS/2 was intended as a <a href="/facts/Protected_mode/y5u3Gwqq">protected-mode</a> successor of <a href="/facts/IBM_PC_DOS/ScsfqAwQ">PC DOS</a> targeting the Intel 80286 processor. Notably, basic <a href="/facts/System_call/NW44AFJr">system calls</a> were modelled after <a href="/facts/MS-DOS/fVrrz1uN">MS-DOS</a> calls; their names even started with "Dos" and it was possible to create "Family Mode" applications – <a href="/facts/Text_mode/641fGn4S">text mode</a> applications that could work on both systems. Because of this heritage, OS/2 shares similarities with <a href="/facts/Unix/0pNL2seI">Unix</a>, <a href="/facts/Xenix/G8sH08Tp">Xenix</a>, and <a href="/facts/Windows_NT/EtccWvxQ">Windows NT</a>. OS/2 sales were largely concentrated in <a href="/facts/Computer_network/3w5RM99p">networked computing</a> used by corporate professionals.
OS/2 2.0 was released in 1992 as the first <a href="/facts/32-bit_computing/TDMVce8s">32-bit</a> version as well as the first to be entirely developed by IBM, after Microsoft severed ties over a dispute over how to position OS/2 relative to Microsoft's new <a href="/facts/Windows_3.1/zYnWyaC6">Windows 3.1</a> operating environment. With OS/2 Warp 3 in 1994, IBM attempted to also target home consumers through a multi-million dollar advertising campaign. However it continued to struggle in the marketplace, partly due to strategic business measures imposed by Microsoft in the industry that have been considered <a href="/facts/Anti-competitive_practices/W3Gt8IQR">anti-competitive</a>. Following the failure of IBM's <a href="/facts/Workplace_OS/4NfBPzRg">Workplace OS</a> project, OS/2 Warp 4 became the final major release in 1996; IBM discontinued its support for OS/2 on December 31, 2006. Since then, OS/2 has been developed, supported and sold by two different third-party vendors under license from IBM – first by Serenity Systems as <a href="/facts/EComStation/0FseHaUf">eComStation</a> from 2001 to 2011, and later by Arca Noae LLC as <a href="/facts/ArcaOS/KGRJJQTA">ArcaOS</a> since 2017.

OS/2 open-in-new

OS/2