Pidgin is an instant messaging program for Windows, Linux, BSD, and other Unixes. You can talk to your friends using AIM, ICQ, Jabber/XMPP, MSN Messenger, Yahoo!, Bonjour, Gadu-Gadu, IRC, Novell GroupWise Messenger, QQ, Lotus Sametime, SILC, SIMPLE, and Zephyr.

Pidgin can log in to multiple accounts on multiple IM networks simultaneously. This means that you can be chatting with friends on AIM, talking to a friend on Yahoo Messenger, and sitting in an IRC channel all at the same time.

Pidgin supports many features of the various networks, such as file transfer, away messages, and typing notification. It also goes beyond that and provides many unique features.

Jabber is best known as "the Linux of instant messaging" -- an open, secure, ad-free alternative to consumer IM services like AIM, ICQ, MSN, and Yahoo, Jabber is a set of streaming XML protocols and technologies that enable any two entities on the Internet to exchange messages, presence, and other structured information in close to real time. Jabber technologies offer several key advantages

Miranda IM is a multi protocol instant messenger client for Windows. Miranda IM uses very little memory and is extremely fast. It requires no installation and can be fitted on a single floppy disc. Its powerful plugin system makes Miranda IM very flexible. Only the most basic features are built in, but there are currently more than 350 free plugins available for download that allows users to extend the functionality of Miranda IM.