I am searching for a CMS that meets the following requirements:
- Based on .NET
 - Works with a tree structure for content items
 - User-defined content types (content templates)
 - Manage external tables
 - Extensible with my own management applications
 - Support for versioning
 - .NET API for content retrieval
 
Note that i am looking for a system that does just content management, i don't need it to handle rendering or supply me with a templating engine. I just want to be able to manage my content and custom applications from one system without writing it myself.
Curious to what you guys would recommend!
/Ruud