shapado - Stackoverflow like QA system in Ruby

Shapdo is a open source Q&A system similar to StackOverflow, Yahoo Answers and some others. It has all the features you would want for a good social Q&A site plus a few more (theming, custom editor), email alerts per questions, following favorite users and one of our key feature is i18n for the UI and for the questions. Tagging and Badging support. Refer the Demo site http://shapado.com/