I have a simple Notepad-like web application I'm making for fun. When you save a document, the contents of a <textarea> are sent to the server via Ajax and persisted in a database.

Let's just say for shits and giggles that we need to compress the contents of the <textarea> before sending it because we're on a 2800 baud modem.

Are there JavaScript libraries to do this? How well does plain text compress in the first place?