Principia Open Source!!

Principia goes Open Source!!
From their twitter:
"We've decided to open source Principia. Lots of code gems in it, including multi-threaded box2d. More info soon."

I don't know what this means, but it surely sounds exciting!!
:D

Wishlist of mod-features:
-Multiplayer
-Speed-up time when you test levels
-More layers
-A drawing tool so you can sketch stuff in edit mode, so it gets easier to make complex shapes.
-Feel free to add more suggestions in the comments!