For GitHub users;

This is a pure-ruby implementation of RFC4122 that I wrote back in

  1. I have touched its internals a few times (mainly bugfixes). I

know someone has already uploaded an old copy of it to GitHub, and thats' 100% legal he has the right to do so, but I believe what I have now is better than the older ones. So I upload this.

It's very tiny (<300 lines ruby code) and you can simply copy lib/uuid.rb to your project. The gemspec file can help you maintain your dependency though.