A web control panel for dns administrators. DNS information is stored in mysql and can be output to either BIND or tinydns files. (C) [GNU/Linux, Unix]

A community project building a free and comprehensive directory service, based on LDAP and DSML standards. (Java)

Open source xinetd/tcpserver based IMAP server for the Linux platform, with support for Maildir.

An Internet search engine, consisting of an indexing robot, a search daemon, and a CGI search frontend. (C++) [GNU/Linux, FreeBSD]

Widely-used DNS server software, and related tools. (C) [Many platforms]

Open source search engine tool released under GPL and designed to organize search within a website, group of websites, intranet or local system.

Open source e-mail filtering solution for Linux e-mail servers. (C, Perl) [Linux, BSD]

A system for managing a variety of directory services, such as NIS, DNS, Samba, Sendmail, and tacacs+. (Java)

Provides IRC networks with definitive nickname and channel ownership, allows messages to be sent to offline users, and gives IRC operators more control. [GNU/Linux, Unix]

Pop 3 server designed to be fast, extensible, and secure. Version history, FAQ, overview, and tarballed source distribution. (C) [GNU/Linux, Unix]