I grew up on a CoCo3; loved that thing as well :) OS-9 Level II was where I first learned a Unix-like OS (on a tiny 6809 machine!) OS-9 Level II was truly a remarkable achievement for such a tiny machine: multi-tasking, windowing, and more. Dungeons of Daggorath was also an epic game. Basic09 was an interesting Basic-dialect that provided more structural programing to the normal sprawling Basic program. And of course who could forget Rainbow Magazine.