Cursor Research has made available the open-source code for Mixture-of-Kittens (MoK), a tool used in the development of its Composer models. MoK combines multiple processes into a single kernel, resulting in faster training times on high-performance computing systems. The tool requires specific types of graphics processing units (GPUs) that may be inaccessible to some users. The release of MoK could provide a boost to researchers and developers working with large-scale AI models. This development matters because it may help advance the field of artificial intelligence by making certain tools more widely available.