And for every Carmack out there that can dream up whole new render pipelines in their sleep, there are thousands and thousands of games that start with a pre-ma

And for every Carmack out there that can dream up whole new render pipelines in their sleep, there are thousands and thousands of games that start with a pre-made engine that in turn i deeply wedded to the DirectX platform. Game engines, much like web browser engines, have become complex beasts. Hell, even as far back ad Wolfenstein 3D i suspect ID Software made as much or more licensing their engine to third parties as they did selling actual games.