Mikrokopter is one of the earliest well-developed multirotor platforms, shipping primarily semi-presoldered kits, but also RTF units through an intermediary. The kits encompass airframes, props, and motors, along with brushless controllers, IMU, variometer, barometric altimeter, navigation, and GPS boards. Half the code is publicly available under a restrictive license (not open development), while the navigation control code is restricted to binary distributions. The MK project was launched in October 2006 by Holger Buss and Ingo Busker, who achieved first flight in mid-2007. A very strong German wiki, forum, and IRC channel exists, but while many things have been translated to English, coverage remains spotty. The closed nav code limits the range to 250m from initialization point for waypointed flight, and turning on waypointed flight after moving outside of the 250m radius manually usually results in a crash.