Blogenine.net released its version 1.6 last day. It is a cool open source blog engine written in C#. You can use XML for the data storage, so that you will not need a database.
This blog is running using the blogengine.net
New features on 1.6 (From official website)
Centralized Comment Management
Automated Comment Spam Filtering with ability to plug-in custom Filtering modules
Multiple Widget Zones (details)
Referrers data and Blogroll items now stored in Database when using the DB blog provider.
Unsubscribe Link in Comment Notification Emails
Referrer Data can be Stored for more than 7 days.
Blogroll items can now be Ordered.
Newsletter Widget more Intelligent - Emails sent when a post is going from an Unpublished to Published state.
Twitter Widget - New options and improvements
Page Slugs now saved in Database.
New Logging system to Track events and errors.
Unhandled Exception Handling
Fixes to Comment Notification Emails not being sent out correctly in some cases.
Outgoing Email improvements
Many other improvements and fixes
Here is the announcement in official website
If you are upgrading check this