Not classic, but free: HP-UX (and the B2000)

www.openpa.net is your friend. Don't have anything that new; a C180 will run standard kbd/mouse and perepherals just fine. What graphics do you have? HP jumped on the next big thing, the EVC connector, really fast. I don't think anybody else did. Finding an adaptor can be fun-. The newer FX5/FX10s I believe have DVI, though. The apps disk does appear to contain cc and cxx. Don't know if they have fixed license policies in place or if you just are asked nicely to get a license from HP. To do that, you either (a) get a commercial software product for HP-UX developed or (b) you send them a check for about $900. HP-UX does have all headers, so GCC is an option if you have cycles to burn (don't even think of using anything less than GCC 3.3 - it seems to, um, "pessimize" programs on RISC architectures) I'll play around with the C180 and check out the apps- I have more disk space there (wohoo! 6GB!)