Universal Time-Sharing System
| Developer | Xerox Data Systems | 
|---|---|
| Written in | Assembly Language (Meta-Symbol) | 
| OS family | Not Applicable | 
| Working state | Discontinued | 
| Source model | Unknown | 
| Initial release | 1966 | 
| Latest release | D00 / Q1, 1973 | 
| Platforms | Xerox Data Systems Sigma 6, Sigma 7, Sigma 9 | 
| Default user interface | Command-line interface | 
| License | Unknown | 
The Universal Time-Sharing System (UTS) is a discontinued operating system for the XDS Sigma series of computers, succeeding Batch Processing Monitor (BPM)/Batch Time-Sharing Monitor (BTM). UTS was announced in 1966, but because of delays did not actually ship until 1971. It was designed to provide multi-programming services for online (interactive) user programs in addition to batch-mode production jobs, symbiont (spooled) I/O, and critical real-time processes. System daemons, called "ghost jobs" were used to run monitor code in user space. The final release, D00, shipped in January, 1973. It was succeeded by the CP-V operating system, which combined UTS with features of the heavily batch-oriented Xerox Operating System (XOS).