I'm reading Programming for the Java Virtual Machine which discusses the Oolong assembler and Gnoloo disassembler. Judging by references online the source code was at one point available, but I can't find it now. Does anyone know where to get it?
UPDATE: thanks to belisarius I have the code, and have put it on GitHub with some build automation to make it a little easier to play with.
Found them here for download.
HTH!
Ps: there are several downloads in the page. The one you're looking for is this