I looked at a number of different options (http://retroramblings.net/?p=1277 http://retroramblings.net/?p=1277) but didn't spend a great deal of time looking at

I looked at a number of different options (http://retroramblings.net/?p=1277 http://retroramblings.net/?p=1277) but didn't spend a great deal of time looking at pcc. I was amazed to discover how many different options there were, actually! VBCC's backend interface is well documented, which helps a lot - and there's a skeleton "generic RISC" backend which is trivial to copy and use as a starting point - I found it very useful to be able to tweak a working backend and observe how the generated code changes, while I was getting a feel for how it all hangs together. VBCC does have an unusual license, however - commercial usage requires permission from the author.