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.
SecureServ is an IRC trojan detector. It's much like a virus scanner, but aimed at IRC networks. Using several methods, including version checks, behavior analysis, and general pattern matching, it aims to detect trojans, viruses, and floodbots which connect to your IRC network. Its "brains" are based on a "Definition file" which contains information on how to detect trojans. To update detection for new trojans, you only have to download a new file.
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.