| Xerox Operating System (XOS) | |
| Developer: | CII |
| Working State: | Historic |
| Supported Platforms: | SDS Sigma series |
The Xerox Operating System (XOS) was an operating system for the XDS Sigma series of computers "optimized for direct replacement of IBM DOS/360 installations" and to provide real-time and timesharing support.[1]
The system was developed, beginning in 1969, for Xerox by the French firm CII (now Bull).[2]
XOS was more successful in Europe than in the US, but was unable to compete with IBM. By 1972 there were 35 XOS installations in Europe, compared to 2 in the US.