Most Active Open Source C# Projects?

Question

I am looking for open source projects being done in C# that are actively looking for developers and does not mind the person coming in from a C++ background. Any pointers appreciated.

Answer 1

There are plenty on codeplex.

http://www.codeplex.com/site/search/openings?query=&sortBy=DownloadCount&tagName=%2cC%23%2c&licenses=|&refinedSearch=true

Answer 2

NHibernate is pretty active project, I am sure they will welcome help. Also SharpArchitecture.net project is always looking for help.