ICQ is an instant messaging software that was first released in 1996. It allows users to send text messages, share files, and communicate in real-time over the internet. The name "ICQ" stands for "I Seek You," reflecting its purpose of connecting people. It was one of the first applications to popularize online chatting. Over the years, ICQ has evolved to include features like voice and video calls, group chats, and social networking elements. While it was once a dominant player in the messaging space, it now competes with other platforms like WhatsApp and Facebook Messenger.