Nope, they don’t all build on CUDA. OpenCL and Vulkan are cross-platform standards developed by Khronos group, the same as who developed OpenGL. OpenCL aimed

Nope, they don’t all build on CUDA. OpenCL and Vulkan are cross-platform standards developed by Khronos group, the same as who developed OpenGL. OpenCL aimed to be roughly the equivalent of CUDA, but in practice the developer experience of CUDA has far outpaced it. Vulkan is targeted at graphics, unlike CUDA. Metal is a similar API to Vulkan, i.e. a low-overhead graphics API targeted at modern GPUs, but only on Apple platforms. PyTorch and Tensorflow are high-level APIs targeted at deep learning, which have multiple execution backends, one of the most popular being CUDA, but they can also run on CPUs or other processors such as TPUs.