Web Pages CMS is a free, open source content management system built using the ASP.NET Web Pages framework. It has been designed to be easy to use, and easy to extend.
And it's all completely FREE!
Web Pages CMS is built upon the Microsoft ASP.NET Web Pages Framework, so it is easy to extend using C# and the Razor syntax in WebMatrix, a free web development tool from Microsoft.
Web Pages CMS uses SQL Server Compact Edition as its default database, making deployment really easy and keeping hosting costs lower.
Web Pages CMS is released under the MIT Licence which means you can do whatever you want with it - even include it within your own commercial projects.