This mod is just a port of the Anvil Fix mod by Onyx Studios, ported both with their permission and within their license. I'll let them do the speaking:
"Anvil Fix removes the level limit of combining Items in an Anvil (vanilla default is 40), so you can repair Items an infinite amount of times or combine enchantments that would otherwise be too expensive to combine in Survival mode.
There's also a config option to remove the cumulative XP cost for repairing.
Note: This mod is technically not needed on the client, but if not present the anvil GUI will show the "too expensive" warning instead of the level cost, even tho combining items will work."
If I am going to port to a later version, your comment begging me won't make me do it faster.
