Mobs killed by players only drop items:
Version: v0.9 (For CB: 1.7)
Damage done by things like Cacti, Lava and suffocation do not yield drops from the mobs. Prevents players from building mob farms by only allowing items to drop from those killed by players themselves.
Bukkit shows how a mob has died, what it died from, albeit a fall, lava, sword... etc This information is what makes NoFarm so simple, so efficient. If mobs are killed by anything other then player damage, the plugin nulls there drops. Really, it's that simple. :) I could sit and type out a bunch of useless information, but it would be thus that useless information. The plugin is so simple.
Bottom line explanation is, it prevents useless unneeded items from collecting everywhere. Which causes huge amounts of lag and tick rate drop. Items dropping from a zombie in a desert because it died from a cacti, is unneeded and will only cause lag. Items dropping from an unattended mob grinder is unneeded and will cause lag. This plugin stops all that and more.
Downloads: https://github.com/Jadedwolf/NoFarm/ 
Source: https://github.com/Jadedwolf/NoFarm/
Changelog http://dev.bukkit.org/server-mods/nofarm/pages/changelog/
Test it out:
If you would like to test the features of this plugin you can do so on this server. IP: http://lagcraft.com
