Bukkit

WordPunishments punishs players for using cusswords with a fine, kill, kick etc.

HexRestrict

Simple system to Prevent some blocks to be used / placed

Prevent Overnight Greifing!

Eliminates terrain damage from creepers

Plugin which allows to buy chunks and more!

ItemRenamePlus

Lets your players report each other

The most effective anti-griefing tool you've ever seen.

A simple, lightweight plugin to stop players from editing the world on your server.

Limit your players abilities to use certain items

A plugin that manages AFK players with a lot of features!

A new way to keep your houses secure :)

Log almost anything.

World border plugin supporting a variety of shapes for each border.

A bukkit plugin to do threaded checks of a player's IP against Open proxies and Tor using publicly accessible DNS Blacklists

PotionFix

Deny people from using the nether portal to the normal world.

Troll your friends and different players!

Warn bad users!