At the seattle alt.net meeting a couple weeks ago there was an interesting talk on encouraging open source in .net.
You can check out the video here: http://www.vimeo.com/3487604
There were a bunch of interesting ideas thrown around, but here are some things that stuck with me.
One lady said that a problem with open source in .NET is that it is too hard to integrate open source tools and libraries with your visual studio environment. The group kind of dismissed this idea, saying that .NET developers are smart enough to add reference a .dll.
However, if you browse projects on codeplex you will find that many of them don’t release a dll download. So you are forced to download a zip file with the visual studio project, build it, and then take the created dll and import it into your project. .NET open source developers need to really focus on the end user experience if they want to see any uptake in their products.
On that same note, codeplex should steal some features from github. Github is much more useful than codeplex because github is prettier, more user friendly, more responsive, has a documentation oriented focus ( you can create wikis, pages, embed images, and whatnot ), you can browse code in your browser. Github is really just great and a .net equivalent would be much appreciated.
Documentation is key if you want your open source project to get uptake. Check out hpricot for an example of a project that is managed very well. It is ruby and its creator really focuses on his explanations and teachings.
There was a lot of doom and gloom in the talk, but really I think there is a lot of good open source .net work being done. Obviously nhibernate, nunit, nmock are very popular projects. Also a lot of cool stuff is going on with the mvc contrib. In the past few years open source in .net has really taken off. The future is bright my friends.