NitrOS-9
The history of NitrOS-9 is an interesting one, taking several twists and turns to its present incarnation.
NitrOS-9 was primarily a creation of three Canadians: Bill Noble, Wes Gayle and Curtis Boyle, starting out as an enhanced version of OS-9 Level Two for the Color Computer 3. It came into existence for one driving reason: to incorporate the then-newly discovered 6309 instructions into OS-9 Level Two.
In its first 6 years of life, NitrOS-9 was sold through various companies, including Northern Xposure and Farna Systems. Into the late 1990s, Alan DeKok took over NitrOS-9 and further enhanced it, fixing bugs and adding new features.
Additional work by Alan and Boisy Pitre over the course of the next few years yielded a revamped NitrOS-9. This "re-released" version became an open source project in 2003, and now supports all Color Computers, including the Dragon 64.