Tencent QQ started off as Open ICQ but then changed its name to QQ to avoid infringing on ICQ's name.
Tencent QQ is the most popularly used instant messenger in China and is used almost exclusively within China. It provides advertisement spaces on its instant messenger windows (similar to adverts on MSN).
There is also a lowcost chinese car called the Chery QQ, once the cheapest car in the entire world (until the Tata Nano of India beat its... nearly unbeatable low price). It was the cheapest car that ever sold in Singapore (at SGD 30,000) and many university-going girls swooned over the adorable QQ. Tencent QQ sued it for infringement, but Chery QQ retaliated saying that Tencent's QQ name did not apply to the auto industry.