mcron

mcron is GNU’s implementation of cron. It is a 100% compatible replacement for Vixie cron.

Anacron

Anacron is a periodic command scheduler. It executes commands at intervals specified in days.

Fcron is a scheduler designed for Unix/Linux systems, especially usefull when your system is not up all the day long.

This program is an “inotify cron” system. It consists of a daemon and a table manipulator.