Flight Control Code

What flight control code is compatible with IR-LOCK?

Recent development has been conducted with flight code based on AC3.3. Also, modified AC3.2.1 flight code is available here. Precision landing with IR-LOCK is a feature that is scheduled for official support in APM:Copter (ArduCopter) version 3.4 (see APM wiki, and developer discussion). So you can find precision landing features in the master branch of ardupilot. Demonstrations have also been conducted with ardupilot-solo.