The Coherent operating system was a UNIX Version 7 clone by the now-defunct Mark Williams Company, originally produced for the PDP-11 in 1980. A port was introduced in 1983 as the first Unix-like systems for IBM PC-compatible computers. Coherent was capable of running on most Intel-based PCs with Intel 8088, 286, 386, and 486 processors and, like a true Unix, was capable of multitasking and of having multiple users.