You can find the latest release of OptiX at https://developer.nvidia.com/optix.
Improvements to 4.1.0
- Support for CUDA 8.0
- Support for Visual Studio 2015 when building the SDK
- Various bug fixes, including more robust handling of complex node graph changes
- Better kernel performance in some cases
- The OptiX headers are now compatible with NVRTC, the runtime compilation library shipping with CUDA