10 Questions w/ Charlie Brown
4. Are there any plans in the works for you to aid Valve in developing their own proprietary engine?
Someday in the future, a full proprietary engine may emerge. The current "Valve" engine has evolved quite a bit from the Quake engine. Valve has spent over 3 years enhancing and modifying the original source code. There was a lot of Valve in Half-Life. :) TF2 is a further modification and I think gamers will be pleased with the result.