Mikrokopter's codebase is not OSS, it is just (mostly) publicly available code, subject to restrictions. The navigation code is completely closed-source.
I see. Thanks.
guess I'll have to write something myself. Anyone know of any good tutorials on control system theory for copters?
That's just Mikrokopter. There are a dozen others. This site is centered on Arducopter, an Arduino-based autopilot. The current version, Arducopter NG, is going to be replaced by Arducopter Mega in a few weeks, so we can use the same hardware & code as the Ardupilot system.
Read up a good bit on the forums and blogs here, so you can get to the really productive questions, and you can probably be building by the time the ACM 1.0 is released.
May I humbly offer my Quadrotor Physics and Control Theory thread:
I will let you know how the story ends when I get there!
There's a lot of folks with neither an engineering nor a controls background who are making good progress with quads. So there's more than just hope :-)