I'm using the Jam to help guide a redo of the framework/engine thing I keep rewriting called Coldsteel. I'll probably be overwriting everything on master shortly as it doesn't quite function anymore and I hate some of the things I did with this iteration of it. There is some code there I'll probably use. Some of it may be useful to others? Check it out at https://github.com/srakowski/coldsteel. I may push what's there to another branch before I destroy it. I have some other repos holding Ludum Dare code that I may draw from for the jam, we'll see :)

This is what i have accumulated through out my jam.
The library have several helper class to help do things like IEnumerable shuffling, Vector2 math, comparing float with small precision, get points that are <North,West,South,East,NorthWest,...> from a point, get direction of a point compare to another point (North,West,South,...)...
The library have a set of simple UI element to help with making UI for the game.
The library have a Screen manager that manage game screen, and screen transition.

The library have a range of drawing thing onto texture2D, you can combine a set of texture, put in an Action<SpriteBatch> to draw on a texture.

The library have a Animation class that help deal with 2D sprite animation.

The library have an implementation of Dijikstra algorithm.

Thanks for sharing ;)