Fcron is a scheduler. it implements most of vixie cron's functionalities. but contrary to vixie cron, fcron does not need your system to be up 7 days a week, 24 hours a day: it also works well with systems which are running neither all the time nor regularly.

fcron also includes a useful system of options, such as: run jobs one by one, run jobs at fcron's startup if they should have been run during system down time, a better management of the mailing of outputs, set a nice value for a job...