Bukkit

GetMobSpawner

AntiZombie is used to prevent spawning creatures in certain areas of your world(s).

This plugin allows you to create simple homes.

NoXP

BetterMining

A simple plugin to turn cows into mushroom cows!

greenstarsonplayer

Allows players to heal and feed themselves.

xArmor

DFlyInvoke allows non-ops (and ops) to fly!

Simple commands to enable/disable player invincibility

Bukkit plugin for simple permissions-based chat channels

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Allows players to claim items, preventing others from picking them up. Vanilla item support only.

With this plugin you can modify the join, leave and kickmessages for normal players or "OP's"

HopperCounter

Stops PlanetMinecraft Trolls

Right-clicking an item frame will print out all information about the item in that frame.

HWF is a plugin that makes it so when any player dies a new world is started

AntiDrop