AuraUAV

http://diydrones.com/profiles/blogs/a-new-use-for-an-apm2-x Includes an advanced 15-state EKF developed by the University of Minnesota UAV lab and has seen action on all their UAV's, on a Lockheed martin project, and on Airborne Technologies (www.atiak.com) projects. Primarily tested on fixed wing aircraft. I figure there is no way I could catch up to the multirotor crowd once I got past that first 90% and was into the nuance and tuning.

https://github.com/AuraUAS