Fcron is a periodical command scheduler which aims at replacing vixie cron, so it implements most of its functionality. It does not assume that your system is running either all the time or regularly: you can, for instance, tell fcron to execute tasks every x hours y minutes of system uptime or to do a job only once in a specified interval of time. You can also set a nice value to a job, run it depending on the system load average, and much more.
