Last friday Eloy and I participated in the Ruby en Rails 2009 Rumble. We had 8 hours to write an application which helped developers find out more information about the dependencies in their Rails application.
Our submission is called Apprise. Apprise is a tool to check gem dependencies and external repositories for newer versions of the currently installed ones in your Rails application.
To be more specific, it looks for three sources of dependencies. Git and Subversion externals in vendor/plugins and bundled Gems in the Gemfile. Checking for Gem dependencies is delegated to Bundler. If you don’t use Bundler to manage Gem dependencies you will still see outdated externals and submodules.
Outdated dependencies are listed and you can decide to update the externals, submodules or gems:
If you want to try it out you can easily install the gem and run the command in the root of your Rails application:
Unfortunately we did not win, but our patch for Bundler to list outdated gems was pulled by Yehuda Katz right after the competition.