Posted by David Given over on Diaspora, an open-source rewrite of CP/M, already running on Amstrad’s NC200 and the Kaypro II:
CP/Mish is an open source sort-of-CP/M distribution for the 8080 and Z80 architectures (although for technical reasons currently it only works on the Z80).
It contains no actual Digital Research code. Instead, it’s a collection of third party modules which replicate it, all with proper open source licenses, integrated with a build system that should make it easy to work with.
By way of illustration David links to this video showing CP/M in use on an NC200 (quick demo of Fortran, Cobol, C, Forth, Pascal, and both MS and BBC Basics):