ICQ is an instant messaging computer program; created by Mirabilis, in the late 1990s.
ICQ users are identified by numbers called UIN, distributed in sequential order (though there are rumored to be gaps in the sequence). New users today will be given a UIN of well over 100,000,000. Low numbers (six digits or less) have been auctioned on eBay by users who signed up in ICQ's early days.
- centericq - supports ICQ, Yahoo!, AIM, MSN, IRC and Jabber
- Trillian - supports ICQ, Yahoo!, AIM, MSN, IRC, Jabber and others
- Gaim - supports ICQ, Yahoo!, AIM, MSN, IRC, Jabber and Gadu-Gadu
- Miranda IM - plugin based, supports ICQ, Yahoo!, AIM, MSN, IRC, Jabber, Gadu-Gadu, BNet, and others
- Fire - supports ICQ, Yahoo!, AIM, MSN, IRC, and Jabber
The name ICQ is a play on the phrase "I seek you".
ICQ allows the sending of text messages, URLs, multi-user chats, file transfers, greeting cards and more.
The Instant Messaging community wishes to remove the proprietary protocol of IMs like ICQ and create a single instant messaging format, called Unified Instant Messaging under the IPv6 Protocol, involving AOL, Microsoft, and Yahoo.
AOL has recently begun making its ICQ software more AIM-like by adding AIM Smilies, as well as introducing cross AIM/ICQ communication. Users on ICQ are able to communicate with AIM users, however such capability is in beta stages.
See also: Red Bend software