Monogame
One framework for creating powerful cross-platform games. The spiritual successor to XNA with 1000's of titles shipped across desktop, mobile, and console platforms. MonoGame is a fully managed .NET open source game framework without any black boxes. Create, develop and distribute your games your way.
Homepage: http://www.monogame.net/
Open Source: Yes
Src: https://github.com/MonoGame/MonoGame/archive/v3.5.1.tar.gz
They also provide a run file for installation - if that helps somehow with building (http://www.monogame.net/releases/v3.5.1/monogame-sdk.run)