NOTE: The version 3 Beta is still a work-in-progress!

Protogame is an open source game engine (MIT licensed) written on top of MonoGame and C#, designed to allow game developers to rapidly produce games within 48 hours.

Read more about Protogame at the website: http://protogame.org/

If you are on Windows, you will need to download and install http://www.microsoft.com/en-us/download/confirmation.aspx?id=30679 in order to compile models.