Land Purification

This mod makes it so that mobs do not spawn infinitely in a chunk. Every time you kill a mob, the 'purity' of the chunk increases. If the purity is high enough, no mobs spawn in the chunk.

This only affects natural spawns, not forced spawns such as from mob spawners and MFR auto-spawners.

Benefits include nerfing mob spawners (they'll still work for a couple minutes), and having a dark base that is safe from mobs, so throwing torches everywhere is unnecessary.

There are two config options:  InitialPurity and DimensionBlacklist.  The initial purity is the number of mobs that must be killed in the chunk for no more to spawn. The dimension blacklist lets you say which dimensions are ignored. By default, the initial purity is 32 and both the nether (dimension -1) and the end (dimension 1) are blacklisted, so without any other mods, this only affects the overworld.

Source at https://github.com/Havvy/LandPurification

There is a version for both MC1.6.4 and MC1.7.2.