Bukkit

[Clearchat] clear the chat with just /c!

Light Weight - Color Chat [1.7.2] (2014)

PerWorldChatPlus

A simple hub plugin that allows you to set and warp to a hub and a clear chat function.

ChatManager+

Chat Guard

allows you to see commands being used by other users.

The best chat channel plugin in Minecraft!

The first Anti-Swear plugin that uses Neural Networks.

RankPrefix+

Control your chat.

This plugin allows you announce/send Titlebar or Subtitlebar as message or on join/firstjoin (also ANIMATED TITLEBAR)

My personal edit

MessageFilter

CrazyLogin

edit all messages of your server

A simple and easy to configure plugin that lets you announce to the server when a new player joins for the very first time.

Private and public chat for admins

Simple broadcasting on your server.

An easy plugin to assign ranks!