EFab is a steampunk styled crafting system. On its own it is not very useful. It is meant to be used in combination with a modpack which configures recipes specific to it (using a json based crafting system). The crafting system has full JEI integration and can support many types of recipes even based on energy (RF), fluids, mana, and so on. There is also a primitive auto crafting system included. You can craft with steam, liquids, gearboxes, processor, RF, and so on. There are monitor blocks as well.
This mod is ideal if you want to have an expert style modpacks where recipes are gated behind other parts and other mechanics.
Preliminary documentation can be found here: https://wiki.mcjty.eu/mods/index.php?title=EFab
You are free to use this mod in any modpack.