Extensible & Open Source ASP.NET CMS: SageFrame
If you are an ASP.NET developer, you already know that there are not too many choices when it comes to finding an open source CMS application.
SageFrame is a good alternative for any looking for such a solution. It is a feature-rich and open source content management system, built with ASP.NET, to create websites easily.
The application enables users to customize/update the websites while browsing by simply interacting with the editable modules.
There is a good-looking admin panel to customize everything; including changing the site design by drag 'n' dropping the locations of the modules, defining new menu items or improving the SEO-friendliness.
SageFrame is modular, it can be extended with modules where you can choose to create them or download the ready-to-use ones.