OS/2

OS/2 is an operating system that was originally made by a joint agreement between the Microsoft and IBM companies. The name stands for "Operating System/2". It was intended to replace MS-DOS and Microsoft Windows. OS/2 was maintained by IBM until 2006. 
IBM discontinued its support for OS/2 on 31 December 2006. Since then, it has been updated, maintained and marketed under the name eComStation. In 2015 it was announced that a new OEM distribution of OS/2 would be released that was to be called ArcaOS.