CLAIM is an AIM chat client library for Common Lisp (using AIM's TOC protocol).
Hopy is a AIM instant messenger written in Java using SWT/JFace. Runs standalone and as an Eclipse plugin. Hopy uses TOC to connect to the AIM network.
IMalizer is, or will be, a generic two part Instant Messenger, with a server that is always connected to the im networks, and a client that connects to the server. Will support ICQ and AIM, and possibly MSN.