ICQ is an instant messaging computer program, which was first developed and popularized by the Israeli company Mirabilis, then bought by America Online, and since April 2010 owned by Mail.ru Group. The name ICQ is a homophone for the phrase "I seek you". 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.ICQ users are identified by numbers called UIN, distributed in sequential order. The UIN was first invented by Mirabilis, as the user name assigned to each user upon registration. The meaning is either Universal Internet Number or Unified Identification Number.