The modules allow to add new code in a flexible way with initialisation, periodic and event functions without modifying the main AP loop.
Also see http://wiki.paparazziuav.org/wiki/Modules
List of available modules
Adcs modules
Ahrs modules
Benchmark modules
Cam_Control modules
Cartography modules
Com modules
Computer_Vision modules
Core modules
Ctrl modules
Datalink modules
Digital_Cam modules
Display modules
Energy modules
Gps modules
Helicopter modules
Imu modules
Ins modules
Light modules
Loggers modules
Meteo modules
Mission modules
Multi modules
Nav modules
Sensors modules
Servo_Switch modules
Sonar modules
Stereocam modules
Misc modules