Tencent QQ, generally referred to as QQ, is the most popular free instant messaging computer program in Mainland China.
The original name of QQ was OICQ (Open ICQ). However, because of the possible trademark infringement with another popular instant messenger (ICQ), and also the fact that neither the program nor the protocol is considered "open", Tencent changed its name to QQ. Because of the lack of openess suggested by the original name (OICQ), some people would also joke about it by referring to it instead as "Oh, ICQ."
It is estimated that there are over 150 million QQ users in China. As of 5 March 2005, there are an average of 9 million people online at any one time on the Mainland China server.
Outside of China, QQ usage is extremely limited, except in South Africa, where it has been used for at least two or three years and has inspired a song by local band The Finkelsteins called "QQ Me". QQ is used by people who want to communicate with people inside those countries. Examples include expatriates, international students and people studying Chinese. Using QQ on the Mainland China Server is known to be a good resource for learners of Chinese, as most Chinese people who use QQ have little contact with foreigners, and may be eager to make foreign friends.
QQ allows free registration for membership. However, the registration was very congested and needed a few retries. In 2002, QQ stopped its free membership registration, requiring all new members to pay a fee. But Tencent reopened the free membership registration in 2003, due to pressure from other instant messengers such as MSN Messenger and Sina UC. Tencent currently offers a premium membership scheme, which offers features such as mobile QQ, ringtone downloads and SMS sending/receieving
Currently, to avoid robot registration, the registration page requires recognization and entering Chinese characters.