CraftTweaker

CraftTweaker is a mod by and. CraftTweaker is the official continuation of 3 by  that allows you to customize modpacks and servers by utilizing a simple scripting language named Zenscript. CraftTweaker is often used to fix conflicting recipes and make mod recipes interact and balance well with each other. CraftTweaker has the ability to add or remove recipes, change mod recipes, alter item names, change furnace recipes, customize the ore dictionary, edit tooltips, and many more things.

The scripting language CraftTweaker uses, named Zenscript, was created for easy use but also offers many more features for the advanced user.