Programs that allow users to "talk" to one another in virtual real time. Users communicate by typing messages which are sent instantly to another person or group within the chat room program. IRC stands for Internet Relay Chat.

Also known as Voice Over IP (VOIP), programs that allow real-time phone conversations over a computer network such as the Internet. The primary advantage of such software is that it effectively eliminates long-distance charges.

Web conferencing is used to hold group meetings or live presentations over the Internet for the purpose of presenting and exchanging information, comparing views, learning, planning, and decision-making.

Programs that add new features or enhance well know application such as Skype or ICQ.

A client which allows instant text and graphical communication between two or more people through a network such as the Internet.