LarryMessenger is a simple to install and easy to use cross-platform instant messenger client. It has a nice graphical user interface, and allows people to communicate over a LAN with static IP addresses without the need for a central server. Furthermore, it provides functions to query the ICQ and AIM networks.
l2mICQ is a Perl-script intended for users switching from Licq to mICQ and vice versa. It pays attention to the flags "visible to user" and "ignore user", and has the ability to only show the difference between both contact lists. This script works for mICQ versions prior to v0.5.
Bicq is an attempt to bring connection to ICQ services to the popular BitchX IRC client. It uses BitchX's built-in plugin system to allow users to connect to and chat on the ICQ system as well as the IRC networks. It runs entirely inside the BitchX application, and uses that application's standard interface with its provided commands.