I actively (when I have time) work on some open-source projects. Both of them are related to the MongoDB C# Driver (to which I contributed a lot of code as well).
The first is FluentMongo (https://github.com/craiggwilson/fluent-mongo) which is a linq provider on top of the driver. This was sucked out of an older C# driver (now defunct) to which I was a core committer with Steve Wagner (http://www.lanwin.de/) and Sam Corder. Writing linq providers is incredibly difficult and I was so proud of my effort in the defunct project that I didn’t want it to go to waste; so I ported it over since the official driver did not have one (and still doesn’t).
The second project is Simple.Data.MongoDB (https://github.com/craiggwilson/Simple.Data.MongoDB). If you haven’t yet played with Simple.Data (https://github.com/markrendle/Simple.Data), then you are missing out. It is completely abusing the point of C# 4’s dynamic keyword to build an Active Record style data layer in .NET. It is a great fit for MongoDB because neither require a schema. Simple.Data was built for a relational database but working with Mark Rendle has been a pleasure and he has changed some of the core to accomodate a different style database.
Anyways, just wanted to get this stuff out there and I’ll keep these updated as I add features to either one.