Regolith is the robot world of “C Programming for Engineers”. You write firmware in C for a small emulated microcontroller, try it on the bench, and flash it into a robot that explores a planet of its own on the class server.
This site will hold the guides and projects that walk you through that work. Nothing is
posted yet, so for now I would start with the SDK and the datasheets on the class server,
in /srv/class/regolith/sdk and /srv/class/regolith/spec.