Capistrano is a standalone utility that can also integrate nicely with
Rails. You simply provide SwitchTower with a deployment "recipe" that
describes your various servers and their roles, and voila! You magically
have single-command deployment. It even allows you to roll a bad version
out of production and revert back to the previous release.

WWW: http://manuals.rubyonrails.com/read/book/17

- Roderick van Domburg