EnchantView by Thebombzen
This mod allows you to see the enchantments you'll receive from the enchantment table before you enchant your item. Note that the server needs the mod for you to see the enchantments in multiplayer.
Enchanted Food Mod by tucsok007
This mod gives you a chance to get enchanted food the same way as you get the original one.
EnchantedBooksCombiner by MrIngelborn
It's a small mod that allows 2 enchanted books with the same and one and only one enchantment to be combined in a crafting table to create a enchanted book with the same type of enchantment but one level higher.
Enchanting Plus by xkyouchoux, odininon, GnR Slash
Replaces the enchanting system with an optional custom one!
Enchantment Revealer by D0SBoots
Reveals all enchantments in the enchantment GUI. Works even with vanilla SMP!
Enchantment Technology by reteo
Enchiridion by joshiejack
This is a mod that started off as part of Mariculture, allowing for loading of custom books from zip files in the configs, handy for modpack creators or people who just want to let people know what's going on, with a mod.