ResEdit... now that's a name I hadn't heard in a long time. ResEdit was really a fantastic tool to do all sorts of tinkering. Too bad pretty much all Mac software is signed now, so this kind of tinkering isn't possible any more.
Quite a memory. I'm fairly certain that using ResEdit to modify and create plug-ins for Escape Velocity: Nova (the sequel to EV Override in the games folder here) is what first got me interested in programming.