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.
A smaller, faster, and easier IM client
Miranda IM is an open source, multi-protocol instant messaging client designed to be very light on system resources, extremely fast and customizable. A powerful plugin-based architecture make Miranda IM one of the most flexible clients on the planet.
Encryption plugin for Pidgin, providing up to 4096 bit RSA encryption using the NSS crypto library from Mozilla. Keys are automatically transmitted and stored, making it very easy to use, but also resistant to man-in-the-middle attacks.
Licq is an ICQ/AIM clone written fully in C++. It uses an extensive plugin system to manage many different functions including the MSN protocol. The main GUI is written using the Qt widget set.
Bot Sentry is a Pidgin (libpurple) plugin to prevent Instant Message (IM) spam. It allows you to ignore IMs unless the sender is in your Buddy List, the sender is in your Allow List, or the sender correctly answers a question you have predefined.
A multi-protocol instant messaging app for Mac OS X
Adium is an Open Source, multi-protocol instant messaging application for Mac OS X. Adium supports AIM, ICQ, Jabber, MSN, Yahoo!, Google Talk, Bonjour, Gadu-Gadu, Novell Groupwise, SIP/SIMPLE (Text), and Lotus Sametime. Additionally, it supports all of these applications at once so, even if you have multiple IM accounts, you don't have to log into each account separately.
pork, oidentd, iplog and ocd
Chat on Facebook without going to the site !
Login to your facebook chat with ease, you can hide the program to tray icon so it doesn't annoy you, it will run and won't slow your PC down no matter if you are rendering a HD video, or playing a high-end PC game. ;)
A pidgin plugin that allows user to assign global hotkeys (e.g. Ctrl+Alt+g) for togglling buddy list and reading queued message. When "Toggle List" hotkey is enabled, it makes the buddy list hidden from your taskbar and task switcher (similar to ICQ).
JAIMBot is a modular architecture for providing services through an AIM client. It contains a generic AIM library and a Bot which uses this library to provide such services as Offline Messaging, Lists, Weather, Headlines, Stock Quotes, AI chatterbot.
Gabber is an easy yet powerful Jabber client for GNOME. Jabber is a powerful open source instant messaging system. Jabber allows communication with other networks, such as ICQ, AIM, MSN, Yahoo, and even IRC, but beyond that it has unique features of its
Fire is a multi-protocol instant messenger client for Mac OS X based on freely available libraries for each service. Currently Fire handles AOL Instant Messenger®, ICQ®, MSN® Messenger, Jabber, limited IRC, Yahoo!®, and Apple Bonjour communications.
Jarl is a Perl/Tk Client. It strives to provide full functionality with every aspect of the Jabber IM system. It currently supoprts messaging, chat, groupchat, ICQ, AIM, and IRC support.
This is an unofficial native port of Pidgin to Mac OS X. It uses native GTK+ (www.gtk-osx.org) which provides better integration and does not require X11. It also comes with more plugins out of the box, including OTR.
OscarLib -- a .NET library that allows a client application to access America Onlines OSCAR (AIM and ICQ) network.
Send XMPP (Gtalk/Google Talk also supported) messages (thanks to Jabber) within a single line of PL/SQL code, get buddies list and status in relational tables (or xml) on Oracle 11g.
Multiprotocol plugin-based instant messenger for X11 (optionaly support KDE), Windows and MaxOS X.
Intercepts and parses all instant message traffic received by the computer. A high performance engine allows conversations to be viewed immediately and/or saved for later analysis. NOTE: Requires WINPCAP
Kopete is a flexible and extendable multiple protocol instant messaging system designed as a plugin-based system.
Pidgin Extended Preferences provides additional preferences for Pidgin users. Most notably, it allows you to change the font size of conversation text without changing your theme and to change how quickly or whether the buddy list tooltips appear.
Kraken is a continuation of the Openfire IM Gateway plugin, but in a way that works for any XMPP server. It provides a way for XMPP users to log into, and communicate through, their legacy IM accounts such as AIM, ICQ, MSN, Yahoo, and friends.
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
This project has re-identified it's purpose to being a host of 'starter' projects for GUI-based Jabber code. To be included, Visual Basic, Visual C++, Borland C++ Builder, etc.
A free Win32 instant messaging client. Smaller, Faster, Easier.
BIM is a Java based AOL Instant Messenger (AIM) Client featuring a full feature Swing GUI. BIM also comes with encryption support. It has a small code base (617KB w/encryption libs) and can be easily dropped and run on wide array of operating systems.