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ICQ is an instant messaging computer program, owned by Time Warner's AOL subsidiary. ICQ was first developed by the Israeli company Mirabilis.

Trillian is a proprietary multiprotocol instant messaging application for Windows created by Cerulean Studios that can connect to multiple IM services

Skype (IPA pronunciation: /skaɪp/, rhymes with type) is a software program created by the entrepreneurs Niklas Zennström and Janus Friis.

Google Talk known as Gtalk is a chat client by Google.

AOL Instant Messenger is an instant messaging application that allows registered users to communicate in real time via text, voice, and video over the Internet. It is maintained by AOL LLC.

A messenger by Microsoft with a new name Windows live Messenger.