Full list of features:

Allows the use of color codes in chat. For example, typing "§1text§rtext" would result in "texttext". This requires the mod to be present on both the client and the server. Enabled by default.
Adds an option that notifies users when they're @pinged in chat. The notification looks like the one generated by the /title command. Disabled by default. Clientside only.
Allows you to change the number of messages to be shown in the in-game chat history. Defaults to 100. Clientside only.
Allows you to automatically remove chat messages using regex filters.
Allows you to automatically modify chat messages using regex substitutions.
Allows you to set a minimum message length. Serverside only.
Allows you to set the default text of the chat GUI.
Allows you to copy messages by clicking them while holding left-control.
Adds a "/enhancedchat clear" and "enhancedchatclient clear" command to clear the local chat history. The client command clears your own chat history, whereas the server command tries to clear the chat history for all users by sending 1000 empty messages.

All features are customizable using the config file or the config GUI. The commands "enhancedchat reload" and "enhancedchatclient reload" reload the config.

Modpack policy:

Just go ahead and use it. Give credit and all that stuff.

EnhancedChat