Universal Time-Sharing System

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 the heavily batch-oriented Xerox Operating System (XOS).
CP-V.
The CP-V (pronounced sea-pea-five) operating system, the compatible successor to UTS, was released in August 1973. CP-V supported the same CPUs as UTS plus the Xerox 560. CP-V offers "single-stream and multiprogrammed batch; timesharing; and the remote processing mode, including intelligent remote batch." Realtime processing was added in release B00 in April 1974, and transaction processing in release C00 in November 1974.
CP-V version C00 and F00, and Telefile's TCP-V version I00 still run on a Sigma emulator developed in 1997. 
CP-R.
CP-R (Control Program for Real-Time) is a discontinued realtime operating system for Xerox 550 and Sigma 9 computer systems. CP-R supports three types of tasks: Foreground Primary Tasks, Foreground Secondary Tasks, and Batch Tasks.
CP-6.
In 1975, Xerox decided to exit the computer business which it had purchased from Scientific Data Systems in 1969. Honeywell offered to purchase Xerox Data Systems, initially to provide field service support to the existing customer base.
The CP-6 system including OS and program products was developed, beginning in 1976, by Honeywell to convert Xerox CP-V users to run on Honeywell equipment. The first beta site was installed at Carleton University in Ottawa Canada in June 1979, and three other sites were installed before the end of 1979.
Support for CP-6 was transferred to ACTC in Canada in 1993. CP-6 systems continued to run for many years in the US, Canada, Sweden, the UK, and Germany. The final system shut down was at Carleton University in 2005.
CP-6 and its accomplishments, its developers, and its customers are commemorated with a plaque on the community wall at the Computer History Museum in Mountain View, California.
Software.
CP-V Software as of release B00, 1974. CP-V was supported by the CP-6 team at the Honeywell "Los Angeles Development Center" (LADC) until 1977 and thereafter.
Contributed Software.
Xerox maintained a library of other Xerox and user-written software from the EXCHANGE user group.