Open the folder Application Support > look for Minecraft.On mac open finder, hold down ALT > click Go then Library in the top menu bar.On windows open Run from the start menu > type %appdata% > click Run.Locate the Minecraft application folder.
Here is a list of the NEI handlers the mod adds:
In fact, the main target of the mod is to stimulate and motivate other mod creators to add handlers for Not Enough Items to their own mods as well as help them to make their unique handers easier and simpler by offering instances. It is a great place to put NEI handers in case the author is impossible to put them into the mods they were created. Firstly, it is a playground to try many new kinds of recipe handlers of Not Enough Items.
