Just this morning, I posted an article about developing and testing system automation with capistrano-cowboy over at the Rails Machine Blog. Check it out :)
Technical.Web
Technical.Projects
Jeweler is the GitHub recommended way to generating and maintaining RubyGem projects.
Homesick is a command line tool for storing your dotfiles in git, and being able to use them locally.
is a Ruby library to help test your library code against multiple versions of a particular gem (ie rails).
capistrano-gitflow is a Capistrano library that provide a git work flow for deploying to staging and production servers based on git tagging.