Kooboo is a developer-friendly CMS that builds on top of ASP.NET MVC.
Kooboo is an open-source developer-friendly CMS which leverages ASP.NET MVC and Razor. It allow for mananing multiple web sites and supports site inheritance. This is especially useful for managing multiple language versions that differ only slightly. It's optimized for complete customizability of HTML markup, CSS styling, and JavaScript-based browser-side features, while still supporting non-obtrusive WYSIWYG editing capabilities for content authors.
Kooboo stores all data in the file system in XML files, which enables scripted batch deployments of whole sites among other things. Also, together with caching it's a cornerstone architectural principle to improve performance when serving static content. Kooboo can be deployed into Windows Azure too, leveraging SQL Azure, BLOB store, and table storage to store site data.
More resources: