Bukkit

NoSpy prevent snooping of your own plugins by other players. It blocks optional and adjustable commands and even the tab auto-completion is blocked in special cases. This keeps the plugins that a server uses secretly and there are less mimicers.

RudelTools

Blocks Creepers And Tnt From Exploding!

Chunk protection plugin designed for ease-of-use.

Want to teleport and check on all your players, but don't want to type commands? This is for you!

Use MrVanish to make it look as though you left the game!

AntiLavaGrief

Juke Alert is an add on to Citadel that lets you create snitches.

OrebfuscatorLite - Anti Xray

City protection Plugin

Bukkit/Spigot plugin for controlling when blocks can be mined

Ban and Mute Manager

SafeWGTool

Tribe management

Stopping those hacks on your Bukkit server.

Stop Bots and Spammers from joining and spamming IP's.

This plugin keeps you chat log clean of spammers, advertisers, and people using full caps.

Disables Players without the given Permission to Craft, Build, break Blocks etc.

Lock chests and doors without commands

Disable any item or block