If you want to run your own weblog or host weblogs, you should definitely give a look at .Text.
Scott has done a great job, and the project moves now to a new level with the release of the source code. Of course it's all built with .NET.
Apart from what you can see on weblogs, I can tell you that .Text also comes with a terrific admin web GUI!
Let this post be one more occasion to thank Scott for all the amount of good work he did!