[eatfish]

It is not other vendors that you need to be worried about. For example, when joining Khronos (OpenGL, GLES and others) you get royalty free permission to use any technology in Khronos' specifications and you, as a vendor, have to offer your tech to other Khronos members for free. I wasn't involved in the DirectX side of things but I imagine Microsoft operate a similar IP framework. There is no practical way to be a GPU vendor today and hoard your IP.

Patent trolls though. A different story. In 5 years we were sued twice (that I know of) by trolls. On both occasions the trolls had some trivial enhancement to a well known technique. I imagine they are operating a mud slinging operation where eventually something sticks. Once it does then either (1) the cost of licensing this 'new' tech is priced less than legal costs or (2) the troll is looking for testimony from some respected entity that the tech is innovative which gives them validation to go after the next biggest vendor up the chain.