Open Source C Communications Software

See https://pidgin.im/about/ for more information. Pidgin is an instant messaging program which lets you log in to accounts on multiple chat networks simultaneously. It runs on Windows, Linux, and other UNIX operating systems. Pidgin is compatible with the following chat networks out of the box: AIM, ICQ, Google Talk, Jabber/XMPP, MSN Messenger, Yahoo!, Bonjour, Gadu-Gadu, IRC, MXit, Novell GroupWise Messenger, Lotus Sametime, SILC, SIMPLE, MySpaceIM, and Zephyr. It is written in C and makes heavy use of GLib and GTK+. Finch is a command line instant messaging program. It also lets you log in to accounts on multiple chat network simultaneously, and it is compatible with the same chat networks as Pidgin. It is written in C and makes heavy use of GLib and ncurses.

A GTK+ Gnutella client, efficient, reliable and fast, written in C. It has been optimized for speed and scalability, with low-memory consumption. It is meant to be left running 24x7, using little CPU and only the configured bandwidth. It is possible to run gtk-gnutella without a GUI or using a shell interface.

Anope Services are built off of the original Epona code written by Lara which is built off of IRC Services. These services have advanced the original Epona code and include new features such as Modules, Mysql, and Defcon Mode.

Claws Mail is a GTK+ based, lightweight, and fast e-mail client and newsreader. Supports POP3, APOP, IMAP, SMTP, SMTP AUTH, NNTP, LDAP, multiple accounts, spell-checking, addressbook, SSL, GPG, filtering, i18n, & more. It is further extended by plugins.

[ Please read https://sourceforge.net/p/darkbot/news/2014/01/darkbots-revitalization/ ] Darkbot is a portable IRC chat robot written in the C language that can be taught responses to user inquiries, and even have conversations with them. Darkbot was originally created by Jason Hamilton as an aid for help channels on Intenet Relay Chat.

A fork of pidgin which aims to provide minor features that have not been addressed by the pidgin development team (including manual textbox resizing). See funpidgin.sf.net for details.

DB Hub is a Linux/Unix software designed to be a Direct Connect hub. It's based on Open DC Hub code but has many more enhancements. Documentation is available on http://dbhub.zendor.eu/ (still incomplete, but updated almost every day)

SimpleCheck is a fast, low resource, server oriented, Windows System Tray based E-Mail Notification Client with a simple UI that regularly checks multiple POP3 E-Mail accounts. Many full client features; immune to viruses; use to delete SPAM mail.

YAM (short for Yet Another Mailer) is a commonly used MIME-compliant Internet mailer written for AmigaOS computers. It supports POP3, SMTP, TLSv1/SSLv3, multiple users, PGP, hierarchical folders, filters, a configurable GUI, an ARexx interface and more...