HarbourMasters have decoded Star Fox 64 back into it's original source code (or close enough) so the game can be ported to anything and modified using normal tools.
Forest of Illusion archival team released a version of the game after Fox McCloud had replaced Sabre, but some characters still refer to him as Sabre and Krystal is playable.
Looks like there might be a fair number of small changes, making a much harder game than the ROM.
Star Fox Adventures hacking gone horribly, horribly wrong.
New light shed on Dylan Cuthbert's time working on Star Fox 2 in Nintendo Life interview.