Jointly developed by Microsoft and IBM to operate with Intel microprocessors, OS/2 was originally a 16-bit operating system. It was designed to work with 286 processors and was first introduced in 1987. OS/2 later became a graphical interface similar to Windows, but also supported a command line. In fact, many OS/2 and DOS commands are the same.

In 1992, a new 32-bit version was released for 386 and above PCs and was solely an IBM product. Later in 1994, IBM released a version it, called OS/2 Warp, that included Internet access and additional features. At the same time, Microsoft was working on OS/2 version 3.0; however, it later became Microsoft Windows NT.

OS/2, especially in its later versions, was regarded as superior to Windows in some areas. Despite this, it never became as popular as Microsoft operating systems, and software developers never created a substantial number of programs to run primarily under OS/2.

IBM officially announces on July 14, 2005, that all sales of OS/2 will end on December 23, 2005, and that all support from IBM for OS/2 will end on December 16, 2005.

src computerhope.com