QQ is a very popular instant messenger software in China. Links to download QQ for Linux:
http://im.qq.com/qq/linux/download.shtml

However, when it runs, it always crash.
(Currently I’m using Ubuntu 8.04LTS)

Edit the following file can solve the problem:
vi /usr/bin/qq
#!/bin/sh

add the following line:
export GDK_NATIVE_WINDOWS=true