OS/2 is an operating system developed by IBM. The name stands for "Operating System/2", because it was intended as the preferred operating system for IBM's "Personal System/2 (PS/2)" line of second-generation Personal Computers. It was originally intended as the successor to MS-DOS and developed together by IBM and Microsoft. As such, in terms of look, feel and features, it is not unlike Windows in many ways; but it also shares similarities with Unix. OS/2 1.0 was released in 1987.

The collaboration between IBM and Microsoft unravelled around the time of the development of version 1.3, when IBM took full responsibility for the project. Microsoft and IBM had originally compromised that IBM would develop OS/2 2.0, while Microsoft would develop OS/2 3.0; but the deal then completely fell apart. Microsoft released Windows 3.1 as its response to IBM's OS/2 2.0. Both Windows 95 and OS/2 eventually supported 32-bit APIs. For details and feature comparisons, see the History of Microsoft Windows page.

Overall, OS/2 failed to catch on in the consumer market, and is today little used outside certain niche markets where IBM traditionally had a stronghold. For example, many banks, especially Automated Teller Machines, run OS/2 with a customized user interface. Nevertheless, it still maintains a small and dedicated community of followers.

Although shortly after the release of Warp 4 in 1996, IBM began indicating that OS/2 would eventually be withdrawn, the company has not published a definite end of support date so far. The lastest IBM version is 4.52 which was released for both desktop and server systems in December 2001. The latest Serenity Systems version, known as eComstation, is 1.1, released in May 2003. IBM is still delivering fixes and updates on a regular basis. IBM urges customers to migrate their often highly complex applications to e-business technologies such as Java, browsers in a platform-neutral manner. Once application migration is completed, IBM recommends to migrate to a different operating system without giving any specific recommendations.

Even though some people had hoped that IBM would release OS/2 as open source, this is unlikely to happen since OS/2 contains much third-party code, most of all, from Microsoft. However, open source operating systems such as Linux have already profited from OS/2 indirectly through IBM's release of the JFS file system, which was ported from the OS/2 code base.

OS/2 continues to be developed and sold, with IBM's blessing, by Serenity Systems under the new name eComStation or eCS.

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1 Technology
2 See also
3 External links


The graphic system has a layer named Presentation Manager that manages windows, fonts and icons. Upon this, lies the Workplace Shell, an object-oriented shell following the Common User Access standards. There are classes representing disks, folders, JPEG files, program objects, printers. These classes are accessible with a SOM interface. There is also a Distributed SOM (DSOM) based on CORBA for remote communication. The component technology OpenDoc was a joint Taligent development with Apple, but it was abandoned after the issue of the Warp 4 version.

The TCP/IP stack is based on the open source BSD stack.

Presentation Manager is similar in function to a non-network version of X11. The WPS then would be like the GNOME environment. SOM has a similar function to COM.

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