OS/2
Operating system
OS/2 is a series of computer operating systems, initially created by Microsoft and IBM under the leadership of IBM software designer Ed Iacobucci. Wikipedia
Initial release: December 1987; 36 years ago
Available in: Chinese, English Language, Italian, and more
Developer: Microsoft Corporation and IBM
License: Proprietary software
Default user interface: Workplace Shell Graphical user interface
Influenced by: MS-DOS, IBM PC DOS