I e-mailed Pelrun just recently about his disassembler DisPel about adding register commenting. He says he will add commenting soon but for now he has put up the source code to the disassembler.
I talked to him about changing the fact that DisPel expects a SNES ROM with a header. If you have a headerless ROM and you try to disassemble, it's off by 200h bytes. Now he says he changed it in the source code where DisPel expects a ROM without a header. If you have a header on a ROM use -n to skip 200h bytes. Although, it doesn't say that he made any changes in the readme.
He also says he converted the source from VC5 to GCC and that it should compile on Linux.
https://github.com/pelrun/Dispel