In July 2011, Skype announced integration with Facebook, so users could see Facebook friends on Skype and see Facebook Chat through both services.Meebo began in 2005 as an instant messaging service accessed via web browser.Multi-user operating systems such as the Compatible Time-Sharing System (CTSS), which was created at Massachusetts Institute of Technology (MIT)'s Computation Center in 1961, allowed up to 30 users to log in at the same time and send messages to each other.
Some institutions, including MIT and Carnegie Mellon University, still use the service.
The 1980s also saw great interest in the bulletin board system, or BBS — a system that allowed users to use a terminal program to upload and download software and exchange direct messages with others.
Founded in 2003, Skype allows Internet users to communicate with others through video, voice and instant messaging.
The instant messaging aspect of the service, while perhaps not its most popular function compared to video conferences, is used by many.
By 2005, AIM dominated the instant messaging market with 53 million users. In 2007, it was estimated that Pidgin had 3 million users. A press release from its launch read, "MSN Messenger Service tells consumers when their friends, family and colleagues are online and enables them to exchange online messages and email with the more than 40 million users of the MSN Hotmail TM Web-based email service as well as with people using AOL Instant Messenger." Microsoft renamed the service Windows Live Messenger in 2005, adding photo sharing capabilities, social network integration and games.