FET is open source free software for automatically scheduling the
timetable of a school, high-school or university. It uses a fast
and efficient timetabling algorithm. It is licensed under GNU GPL.

Usually, FET is able to solve a complicated timetable in maximum
5-20 minutes. For simpler timetables, it may take a shorter time,
under 5 minutes (in some cases, a matter of seconds). For extremely
difficult timetables, it may take a longer time, a matter of hours.