Whenever: A Ruby DSL for Defining Cron Jobs
It has always been a trend with Rubyists to take things that have poor interfaces and give them better ones. Javan Makhmali from Inkling Markets has lived up to this trend, and given us Whenever, a library that wraps cron's syntax with a Ruby API (cron being a UNIX task scheduling tool).
Whenever can be tightly integrated with Rails (providing application specific commands such as "rake" and "runner" from the API – see an example here), but can also be run as a standalone program. Whenever outputs valid crontab syntax, and can even write the crontab file for you!
Whenever helps you keep your cron jobs with your code so that there is no separation of logic. Since Whenever is a wrapper for cron, however, it's really focused on on UNIX and UNIX-like machines. While there are some cron implementations for Windows, Whenever wasn't really designed for this purpose.
Note: This post was written by Ari Brown.