Konversation is a simple and easy-to-use IRC client built on the KDE platform with support for SSL connections, strikeout, multi-channel joins, away/unaway messages, ignore list functionality, full Unicode support, the ability to auto-connect to a server, optional timestamps in chat windows, configurable background colors, and much more.
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.
superseriousstats is a small and efficient program for creating a Web page with statistics from various types of IRC logs. It keeps track of its parse history and only processes new activity before storing any accumulated data in a SQLite or MySQL database. It is suitable for high volume IRC channels and large log archives, and is relatively easy to integrate with IRC services (e.g. bots) that interact with the database and provide last seen information and many other statistics directly in your channel.
KVirc is a Visual Internet Relay Chat Client based on the Qt library. Features include a MDI user interface, drag & drop, built-in scripting language (aliases, popups and events), customizable backgrounds and colours, DCC (chat, send with resume, voice), CTCP functions, mIRC colour support with preview, notify list, online help and configurable logging.
pidgin privacy please is a pidgin plugin to stop spammers from annoying you. You can block messages from certain users, block messages from people who are not on your contact list, and suppress repeated authorization requests. Optionally, senders of blocked messages can be notified with an auto-reply.