Open Source MTM?

So I have been working with Microsoft Test Manager 2010 and it can be really buggy at times. MTM is used with Visual Studio and c# so I was wondering if there was a solution to use with ruby. The library Watir(Web Application Testing in Ruby) can be used with ruby the way watin is used with .net. But no one I worked with really knew of any open source solutions like MTM to manage test cases. I am thinking about looking into it more later.