Atomic IRC is described as 'Atomic is an open source IRC client built for a new age. New features from its heritage of Yaaic, improvements and stuff' and is an app in the Social & Communications category. There are more than 50 alternatives to Atomic IRC for a variety of platforms, including Windows, Linux, Mac, Online / Web-based and Self-Hosted solutions. The best alternative is Pidgin, which is both free and Open Source. Other great apps like Atomic IRC are HexChat (Free, Open Source), Trillian (Freemium), Adium (Free, Open Source) and mIRC (Paid).
mIRGGI is the first IRC client for S60 3rd Edition devices. It is also available for 2nd edition devices. It is currently in early stages because I just began writing it on 10th of March. Ive been meaning to do this for a long time but havent gotten to it.
wsIrc - the global community communicator, goal is to offer a free web IRC client which should be at the end as good as old standalone application, but yet without requiring any installation, without any update, without any virus risk, and maybe we will offer yet a few...
Floe is an IRC client written in C#, using the .NET 4.0 framework with WPF technology. It is inspired largely by both XChat and mIRC, and one of its distinguishing features is the ability to choose which layout style to use (tabular like XChat or flow like mIRC).
The sushi IRC suite consists of a central daemon and several clients, which communicate via DBus. The daemon -- maki -- provides DBus methods and signals that abstract the IRC protocol to make it more pleasant to use.