The all-purpose addon dependency for SuperTux that allows you to make custom enemies and objects, ease the pain of scripting, and let you make more stuff for SuperTux than was ever possible before.
Liborange was recently rewritten from the ground up. Thanks to this the code now has documentation comments for basically everything. However, this does mean addons that used the old version of liborange (AKA just Industrial V2) are no longer compatible. Some features also arent there any more, like the script loader, but these will come back in the future when I get around to making them.