In the software context, the relatively simple OSs for early microcomputers were usually inspired by minicomputer OSs (such as CP/M's similarity to Digital's single user OS/8 and RT-11 and multi-user RSTS time-sharing system). Also, the multiuser OSs of today are often either inspired by, or directly descended from, minicomputer OSs. UNIX was originally a minicomputer OS, while Windows NT kernel—the foundation for all current versions of Microsoft Windows-borrowed design ideas liberally from VMS. Many of the first generation of PC programmers were educated on minicomputer systems.