Lineo, spun off from Caldera, spun off from Novell (did I miss a step there?), who purchased Digital Research (or at least a lot of Digital Research’s assets) has made everything CP/M-related available for free.  The unofficial site is at http://www.cpm.z80.de.  The site contains lots of very cool stuff:  full binaries for a large number of CP/M distributions and Digital Research programs (Pascal MT+, for example), source code for many CP/M versions, and some very difficult to find documentation.  This is, according to the site’s maintainers, everything that Lineo has related to CP/M.  Apparently much of it has been lost over the years as ownership of the properties moved from company to company.  That’s unfortunate, as I would sure like to see the source for the Pascal MT+ compiler.  About the only Digital Research product missing from the site is DR-DOS.  Lineo has held that one back.  Apparently it’s still a saleable product.

I doubt that CP/M is much in demand these days, although you never know with embedded systems.  If nothing else, the released source code has historical interest.  It’d also be interesting to study some of the techniques they used to save space and reduce processor usage.  Remember, CP/M had to operate on 8080-based computers running at 1 MHz with less than 64K of RAM.  It’s amazing how far we’ve come in 20 years.