UTS is a discontinued implementation of the UNIX operating system for IBM mainframe (and compatible) computers.
UTS Release 4.5 supports the following S/390 model processors and their successors: The UTS project had its origins in work started at Princeton University in 1975[2] to port UNIX to the IBM VM/370 system.
Team members there were Tom Lyon, Joseph Skudlarek, Peter Eichenberger, and Eric Schmidt.
[3] Five years later, IBM announced its own mainframe Unix, IX/370, as a competitive response to Amdahl.
[4] The commercial versions of UTS were based on UNIX System III and UNIX System V. In 1986, Amdahl announced the first version to run natively on IBM/370-compatible hardware, UTS/580 for its Amdahl 580 series of machines; previous Unix ports always ran as "guests" under the IBM VM hypervisor.