Webbynode is a very affordable VPS host (256 RAM for $15) which has great support for Rails applications.
Rfm brings your FileMaker data to Ruby with elegance and speed. Now your Ruby scripts and Rails applications can talk directly to your FileMaker server with a syntax that just feels right.
Capistrano recipes for database backups before migrations, passenger deployment strategy, release tagging in Git repos.
Debugging toolbar for Rack applications implemented as middlewa
Anonymous Pro (2009) is a family of four fixed-width fonts designed especially with coding in mind.
Trample is a more flexible load simulator. Instead of a static list of urls, trample's configuration language is ruby. Using ruby's blocks (lambda functions), it's possible to randomize the requests that get made in each thread, as well as the user that logs in.
Or, you can test your Rack application (or Sinatra, or Rails, or Merb) using arbitrary HTTP client libraries, to check interoperability.
Page Speed is an open-source Firefox/Firebug Add-on. Webmasters and web developers can use Page Speed to evaluate the performance of their web pages and to get suggestions on how to improve them.
This article describes a technique for overriding the equals method that preserves the contract of equals even when subclassses of concrete classes add new fields.