Bukkit

This will display all online staff.

BasicChat

ModifiedMSG replaces the /msg command of the default minecraft msg command

Admins can leave custom notes for players to see when they join!

MultiL - Multi Language support API for your plugins!

Replaces swear words with custom other words/phrases!

Essentials XP Chat Prefix (1.8)

BroadCaster

A plugin to temporarily disable chat for all non-admin players

This plugin will allow you to test if your server has lag on it.

A simple to use plugin designed to prevent spam

Chat System

A simple and friendly chat bot :)

Better /tell command usage.

CustomJoin-LeaveMSG

LinkDeaths is a multi-world death message plugin

A small admin chat modification for bukkit.

Login plugin to display a custom login/logout message

Minecraft Web Chat

UnicodeChat