Cursor open-sources Mixture-of-Kittens MoE training megakernel

Cursor released MoK under Apache 2.0, an MoE training megakernel for NVL72s claiming up to 2.37x speedup over the strongest public baselines by fusing communication and computation into a single deterministic kernel. Reddit skeptics caution the claimed ~40% end-to-end gain may not hold against naive kernels.