If you are looking for the decompiler itself, visit https://github.com/jindrapetrik/jpexs-decompiler
NEW : We have got a new blog where we post some interesting SWF internals info.List of issues
#1383 Debugging nested SWFs
Some SWFs contain SWFs embedded in them as binaryData, which to my very pleasant surprise FFDec recognizes and handles. Would it be technically possible to set breakpoints in these during debugging?
Somewhat relevant but not really helpful: https://stackoverflow.com/questions/718066/whats-the-best-way-to-debug-an-inner-swf-thats- loaded-from-a-non-debug-outer-s