Quassel IRC is a modern, cross-platform, distributed IRC client, meaning that one or more clients can attach to and detach from a central core, much like the popular combination of screen and a text-based IRC client, but graphical. In addition to this unique feature, it aims to be a comfortable chatting program.
ircproxy is an Internet Relay Chat Proxy, which works as a layer between your IRC client and the IRC server. It features bouncer capability and has more features, flexibility, and configuration options than other tools. It also includes an option to use the system password list instead of requiring a separate password database.
CWirc is a plugin for the X-Chat IRC client to transmit raw Morse code over the internet using IRC servers as reflectors. The transmitted Morse code can be received in near real-time by other X-Chat clients with the CWirc plugin. CWirc tries to emulate a standard amateur radio rig: it sends and receives Morse over virtual channels, and it can listen to multiple senders transmitting on the same channel. Morse code is keyed locally using a straight or iambic key connected to a serial port, or using the mouse buttons, and the sound is played through the sound card, or through an external sounder.
ngIRCd is a portable IRC daemon written from scratch. It is easy to configure, supports server links (even with original ircds) and runs on hosts with changing IP addresses (such as dial-in networks). Currently supported platforms are AIX, A/UX, Darwin/Mac OS X, FreeBSD, HP-UX, IRIX, Linux, NetBSD, SunOS/Solaris, and Windows with Cygwin.
TR-IRCD is an ircd and a collection of services programs for IRC networks. The ircd is heavily influenced by ircd-hybrid and Bahamut. It includes support for IRC extensions such as md5-encrypted hostnames, modules, threads, different protocols, channel modes, and languages. It supports IPv6 and Web-based configuration, and includes a proxy scanner.