Meta releases open weights of the 816-billion-parameter Muse Spark Open; with Apple it shows the model running on two Mac Studios
Prepared by Sintelligent with the help of SI. Published in SI: . Updated: .
One of the largest open models from the US is now available to everyone and can run on two powerful desktop computers without the cloud; the license, however, is not as free as classic open source.
Meta has published the weights of Muse Spark Open, a multimodal (text, images, audio, video) mixture-of-experts model with 816 billion parameters, 42 billion of which are active per token, and a context window of up to a million tokens; it is built for programming and long agent tasks. Meta calls it the most capable open model from a US lab; according to SiliconANGLE, in Meta's own table the model scored 61.8 on the JobBench agent test (Thinking Machines Lab's Inkling scored 31.1) and 89.2 on the MCP-Atlas tool-selection test, but on the Terminal-Bench 2.1 coding test it scored 76.4 against 85 for China's Kimi K3; Meta promises a full evaluation report later. The license is the new Muse Model License with "limited commercial terms": companies that sell the model as a hosted service and have more than $20 million in revenue over 12 months sign a separate agreement, products must carry a "Built with Muse Spark Open" label, and the license excludes military use and critical infrastructure. Together with Apple, Meta showed the model running on two Mac Studios with M5 Ultra chips linked through MLX (about a terabyte of memory between the two); CNBC writes that two to four machines can be linked, and Zuckerberg and Apple's new chief executive John Ternus publicly backed each other's work. Meta's strongest models remain closed.