Tony Tamasi, NVIDIA director of Content and Technology, told Bit Tech that he doesn't have a particular preference to what physics library game developers use, as long as it runs on NVIDIA's GPUs.
"In the end, we decided to acquire Ageia because they'd already got a really nice SDK designed for parallel processing - we just did a C for CUDA implementation and we've been doing that ever since. We've also been helping the Bullet Physics guys with their GPU implementation - it's based on our OpenCL samples and they've been using Nvidia hardware to do their development.
"Anyone who wants to do physics on the GPU is all goodness for us, so if the Havok guys get around to doing some OpenCL stuff on the GPU, that's good for Nvidia. All we really want is to see lots of GPU based implementations - we did the PhysX thing because we wanted to get the ball rolling."