SubText is an open source Blog engine written with the Microsoft NET framework. Actually my English blog and also my italian blog are working with this blog engine.
After one year is out the new version, 2.0.
You can find the download here.
Simone Chiaretta a good friend of mine is one of the Developer contributor of this project, and he has released a series of posts about the new future in his blog:
If there is someone like me that are still using subtext in the version 1.9.5 or less, you can find here a detailed article about the upgrade procedure.