The first version of the program was released in November 1996 and ICQ became the first Internet-wide instant messaging service, later patenting the technology.AOL acquired Mirabilis on June 8, 1998, for US$407 million.
In April 2010, AOL sold ICQ to Digital Sky Technologies for $187.5 million. According to Time Warner, ICQ has over 100 million accounts registered.
- ICQ features include sending text messages, offline support, multi-user chats, free daily-limited SMS sending, resumable file transfers, greeting cards, multiplayer games and a searchable user directory.
- ICQ6 was launched on April 17, 2007, and offered a single communication platform that combines the various user options: instant messaging services, free SMS from ICQ to mobile, voice and video communication. The software's new sound gallery was orchestrated by the Israeli psychedelic trance duo Infected Mushroom. Among the new additional features in ICQ6 are Quick IM, which allows users to send a short message without opening a conversation window, a "follow me" service directly to the user’s mobile, a multi-chat service and Zlango support, the animated icons language.