QQ is Tencent's IM/presence and social network system. It is widely used in China, especially in mobile space. It has the biggest number of users in all IM systems in the world. It the second IM system after ICQ (and AIM). Also big in South Africa apparently.

QQ used to be supported in libpurple, but it no longer is. There is a Pidgin plugin for QQ.

The QQ2010 protocol has been reverse engineered and documented here.

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