What is it?
Zaggit is a simple, server-less instant messenger. It runs only over a local network and lets you send and receive public or private messages.
How do I use it?
Using Zaggit is simple: install it, run it (make sure it's allowed to get through your Windows firewall!) and start typing messages :)
When users are online, they will appear in the Online list on the right hand side. You can double click a user to send them a private message (a normal message, just prefixed with @Username).
Zaggit runs in your notification area. When you close (rather than quit) the message window, new messages will pop up a balloon notification.