#“MongoPress - A MongoDB-based CMS inspired by WordPress”
These guys started out building a plugin for WordPress to make it use MongoDB instead of MySQL but found it was almost impossible. So they decided to build an alternative called MongoPress based on many of the good things about WordPress and hopefully none of the bad things (Die-WordPress-Editor-Die-Die-Die).
It's early days but it looks interesting so far. I'll play around over Christmas and see how it scales.