The source code of a few versions of CP/M was released a couple of years ago:<p><a href="http://www.computerhistory.org/atchm/early-digital-research-cpm-source-code/" rel="nofollow">http://www.computerhistory.org/atchm/early-digital-research-...</a><p>The accompanying article does a good job of putting CP/M in its historical context describing what it actually was. But other than nostalgia (and those who have sacrificed their eternal souls to WordStar), there isn't much of a reason to actually <i>run</i> CP/M itself. There's not a lot to see there - if you've ever used the MS Windows shell, imagine its Paleolithic ancestor.