(Operating System 2)- A rival PC- operating system- to Microsoft Windows, produced by IBM in the 1990s. It still has a small, dedicated core of supporters, but didn’t catch on and for most purposes is obsolete.
A protected-mode, virtual memory, multitasking operating system for personal computers based on the Intel 80286, 80386, i486, and Pentium processors. OS/2 can run most MS-DOS-based programs and can read all MS-DOS disks.