A universal instant messaging (IM) program
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.
Psi IM — Qt-based XMPP/Jabber client
Psi aims to be a feature-rich Jabber/XMPP client for novice and experienced Jabber users. There are builds available for MS Windows, GNU/Linux and macOS.
Audible Alerts is a Pidgin (libpurple) plugin to produce notification of an IM audibly. It uses eSpeak, a text-to-speech program, to call out the name of the buddy who IMs you. You can download eSpeak from www.sourceforge.net/projects/espeak
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.
A cross-platform multi-service chat and instant messaging GUI client in C++/Qt.
ChatCaptain aims to be an alternative to the chat clients not only available on Linux, but also an alternative to the non-free(and free alike) chat clients available on Windows.
Miranda IM in Polish
PHP Jabber Bot open source. Minimal requirements: PHP > 5[CURL, ICONV, SOCKETS opened 5222 port], MySQL Included many plugins: google, horo, news, translate and more...
climm is a portable, small, yet powerful console based, fully internationalized instant messaging client supporting the current v8 ICQ protocol and XMPP.
Engroup is the web enterprise groupware promotes various collaboration methods plus adding company business management modules. Features are included: CRM, HRM, Document Management, Project Management, Chat, Wiki, Forum, News, Todo.
imEcourse is a course electing system for college students.It bases on IM.Including executable application IM and web-IM. To use IM to elect course?Of course!