Yes, yes, it’s a Tool-Assisted Speedrun. It’s a whole different thing from regular speed runs, although those can be pretty spectacular too (Portal single-segment in 13m06s, Super Metroid in 32m). The Super Mario 64 time attacks are getting to the ridiculously optimized state that until this point few games attain in the scene — Mega Man and the Sonic games are getting close. Just watch and enjoy.
I hope you really like the sound of Mario going “ya-hooo!”