MTLib is a library mod for CraftTweaker addons, available for Forge on Minecraft 1.10.2–1.12.2. Addon authors do not have to use it, but its helpful methods and classes make development easier, including ModTweaker utilities, IUndoable action classes, and base “dump” command classes.
For addons that use this library, rent your own Minecraft server and install MTLib with one click from the server panel.