Concurrent DOS (1984) 6 CPM

Originally an optional module for Concurrent CP/M-86 3.1, this version of Digital Research's CP/M provided basic compatibility with PC-DOS in 1983. Simple DOS applications that did not require hardware access can be ran on this. A stripped down single tasking version was released as DOS Plus and later DR-DOS.

• XM 6.x
• 386 2.x
• 386 3.x

WordStar (1981) 23 Word Processor DOS CPM

WordStar, originally from MicroPro, was a popular word processor during the early 80s. It was ported to a number of CP/M architectures as well as Unix and PC/MS-DOS. It competed directly against many word processors, including WordPerfect, Microsoft Word for DOS, and Multimate. By the late 80s most business word processing had moved to WordPerfect. In the early 90s, Microsoft Word for Windows took over.

• 4.0