- https://dev.px4.io/v1.9.0/en/concept/architecture.html -Very Good
PX4 vs Ardupilot
MoveIt for UAVs?
Although most people use MoveIt for manipulators, it is also capable to plan motions for mobile bases, Autonomous Underwater Vehicles (AUVs) and Unmanned Aerial Vehicles (UAVs). In  a 3D navigation system is presented for precision agriculture. Using a Unity-based simulation environment, a MoveIt-based system is presented for multi-level navigation that is flexible and robust enough to deal with complex, dynamic environments.
 L. do Ó, P. Alexandre Prates, R. Mendonça, A. Lourenço, F. Marques and J. Barata, “Autonomous 3-D Aerial Navigation System for Precision Agriculture,” 2019 IEEE 28th International Symposium on Industrial Electronics (ISIE), Vancouver, BC, Canada, 2019, pp. 1144-1149.