TilkIRClog is a program designed for logging chats on IRC channels, written in Python. It doesn't intend to be an IRC client, so it's fully automated and has many useful features. For example, it can automatically send logs via e-mail, and even compress them. It can also be restarted from a cron job after termination.
YSM (You Sick Me) v7 is an ICQ console client. It was originally meant to run in Linux, but it has been successfully tested in Linux, BSD, Win32, BeOS, and QNX. The client requires no extra libraries, and is written in the C language. YSM is based on the last ICQ protocol version, v7/8.
LostIRC is a simple, yet very useful IRC client. It has features such as tab-autocompletion, multiple server support, automatic joining of servers/channels, and DCC sending, which should cover the needs of most people. Another design goal is 100% keyboard controllability. LostIRC was written using the gtkmm GUI library.
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.
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.