Z80 BBC Basic by R.T. Russell is now open source
-David Given who is the author of CP/Mish (CP/M for Notepad NC200 using disk drive) did obtain from Richard Russel author of the Z80 BBC Basic that this version becames open source (Zlib license) and so available on CP/MIsh's github.
You can read the history of the BBC Basic on Richard Russell's web site.