This work is described in the following paper
MCX (implemented with NVIDIA CUDA), MCXCL is written in the OpenCL framework, and is capable of launching parallel photon simulations on most modern CPUs and GPUs produced by many vendors, including NVIDIA, AMD and Intel.
3 benchmark problems (and 3 optimizations) is shown in the below figure. MCXCL is currently about 2x-3x slower than MCX (CUDA based) on NVIDIA GPUs (see the inset). This is a result of lagged OpenCL driver development of NVIDIA. On the other hand, MCXCL performs quite well on AMD and Intel processors.
Pre-compiled MCXCL binary packages (preview version) for Linux/Windows/MacOS can be downloaded here. The current preview package is named "mcxcl-*-git_20171108.zip".
However, you are highly recommended to download the MCXSuite.zip package for each platform (Linux/Windows/MacOS). MCXCL is part of the suite and easy-to-use GUI interface (MCX Studio) is provided to help one design new simulation and review results. After downloading and extracting the MCXSuite package, please start the GUI program by executing the "mcxsuite(.exe)" executable inside subfolder MCXSuite/mcxsuite/mcxsuite/.