One of the most advanced physics simulation SDK in the game development world, PhysX was exclusive to Nvidia GPU's for a very long time. And the AMD GPU owners were unable to use these effects on their cards. But today, Nvidia finally make the PhysX open source so all developers will able to use these effects on any GPU hardware.
NVIDIA open sources PhysX
PhysX was already used by many games but can be only calculated via CPU because of the limitations. But after its become open source, developers can utilize the GPU on every hardware. And we already see many years ago, GPU PhysX can deliver much more realistic effects than CPU one.
Nvidia also announced PhysX SDK 4.0, but it will remain to Nvidia GPU's for now.
You can watch the PhysX SDK 4.0 trailer below: