The full documentation is in the beignet-dev package. Summary of known issues: Beignet upstream is now mostly inactive, as it is being replaced (for Broadwell and later hardware) by Intel Compute Runtime (intel-opencl-icd). In particular, future hardware will probably not be supported in Beignet. Discrete GPUs often disable the integrated GPU, preventing this package from working. It may or may not be possible to re-enable it (https://nouveau.freedesktop.org/wiki/Optimus/). Float literals must be in the '2.3f' form; plain '2.3' is a double literal, and double precision is not supported. By default, no single OpenCL kernel is allowed to run for more than 6 seconds, to prevent accidental hangs: if "dmesg | grep hangcheck" finds anything, this limit has been hit. You can turn it off with "echo -n 0 > /sys/module/i915/parameters/enable_hangcheck" (as root). cl_khr_gl_sharing is only partially implemented.