Ignore AISS, it doesn't need it (I'd edit my previous post but it won't let me). Ignore the readme, the package is created from the OS4 sources so that's what the readme says it needs. friend_bitmap probably isn't needed now either, I think I forced that on for RTG in the latest build.
Just tell me what requirements those have to meet that want to help/contribute.
The main thing right now is fixing the optimisation bug in GCC. It optimises away NewObject's taglist which means I can't build with optimisations on, which makes it slower and means there's no Javascript.
Other than that, general optimisation and bug-fixing in C, especially wrt rendering. I'm happy to slot hand-crafted 68k asm in if somebody wants to write it!