Monit is a free software tool for monitoring processes on Unix and Linux systems. With Monit, the state of the system can be viewed directly from the shell, or via your native HTTP (S) web server. Monit reached its popularity with Ruby on Rails and the Mongrel web server, due to the need to have a tool that could handle the many identical Mongrel processes that are required to keep a Ruby on Rails site scalable, so that Monit was in practice only created to meet the needs of the Ruby on Rails community Many popular Rails sites have used Monit, including Twitter and Scribd.

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