JabberTools is a set of console and Web-based Perl tools depending on Net::Jabber that makes it easier to use Jabber and convert to using Jabber from other instant messaging systems (e.g., AOL and ICQ). The tools include a Jabber account manager and an importer that converts your previous contact lists/rosters/buddy lists into your Jabber roster.
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.
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.
kicq is an ICQ client specifically designed for the KDE desktop. It has a simple, clean interface very similar to the original Windows ICQ client, and includes all of the most commonly used ICQ features such as messaging, real-time chat, and file transfer. It features complete message history, a New ICQ User registration window, multiple ICQ accounts, SOCKS5 proxy inline support, configurable sound events, Cyrillic koi8-r/cp1251 recoding, and support for the ICQ UDP v5 and ICQ TCP v2 protocols.
icqlib is the most feature complete, open source, library implementation of Mirabilis' ICQ protocol available on the Internet. It currently supports most of the ICQ UDP v5 and ICQ TCP v2 protocols, including new UIN registration, chat, and file transfer. It was written in C for portability, and supports multiple simultaneous connections to ICQ servers, SOCKS5 firewalls for both UDP and TCP protocols, an event-driven, non-blocking interface, and the Russian language (automatically performs conversion from Windows 1251 encoding to Unix koi8 encoding).