CraftTweaker is a Minecraft mod that allows modpack authors to customize the game, allowing for new recipes to be added, old ones to be removed and just general modpack customization!

CraftTweaker uses a custom scripting language called ZenScript, which is a fairly easy to learn language that fits CraftTweaker's needs more than an already existing language would (such as JavaScript).

This site will hopefully help guide you through everything that is possible with CraftTweaker, all that would be left is for you to use the knowledge and create something amazing!