Kashyyyk
A Work-In-Progress, Full-Featured, Open Source IRC Client
...Kashyyyk also has very few external dependencies, the official binaries statically linking all supporting libraries.
Kashyyyk is natively available for OS X, Windows, and FreeBSD. Additionally, it can be compiled for Cygwin/X.
When possible, Kashyyyk takes advantage of native OS capabilites, such as the OS X notification center.
Kashyyyk uses the libfjirc library originally written for the Whittler IRC bot and the libfjnet wrapper written for TurboSphere. It has an FLTK-based GUI. Kashyyyk is intended to be cross platform and easily compiled. It is known to compile using Clang, GCC, Cygwin, Sun Studio, and MSVC 2013.