QQ for Linux was released 31st of July 2008 and it is the first time that Tencent has supported Linux officially with a QQ client. Currently QQ for Linux is still in Preview phase, but already seems to support all the basic features. There are 3 versions available for download (about 4.7MB):

1. Deb version for example for Ubuntu
2. RPM for SuSE 9 and Fedora Core 8
3. .tar.gz version for other distributions

 Installation instructions are documented shortly on the (Chinese)  help page :

Language:

I believe Chinese only at the moment.