I know that you are a rails guy and they use an MS stack. Any friction there? Were they able to use your A/B framework or did they have something on their own stack?
Edit: Nevermind: http://blog.fogcreek.com/how-to-do-ab-testing-using-google-w...
I enjoy Rails a lot more than I enjoy .NET, but give me some credit: looking at new languages doesn't cause my brain to throw a WTFCodeIsCamelCasedException.
By the way, Fog Creek isn't strictly a MS shop. There is a lot of "best tool for the job" going on, including e.g. Python being used as utility glue.