How to connect to the QQ Messenger network?

You can find the download page at http://im.qq.com/qq/linux/download.shtml or if you just want the direct link to the .deb package:

http://dl_dir.qq.com/linuxqq/linuxqq_v1.0.2-beta1_i386.deb

There is a recently developed plugin for Pidgin that works quite well. Basic things such as chatting, buddyicons and sending files are all supported. You can use it by adding ppa:lainme/pidgin-lwqq to your repositories and then install pidgin-lwqq. After that WebQQ shows up in the list of protocols to choose from when adding a new account in Pidgin.

sudo apt-add-repository ppa:lainme/pidgin-lwqq
sudo apt-get update
sudo apt-get install pidgin-lwqq