Meta releases Muse Spark Open, an 816-billion-parameter open-weight model it says runs on two Apple Mac Studios

Meta released the weights of Muse Spark Open on 15 October, describing it as the most capable US open-weight model to date. It is natively multimodal with 816 billion total parameters (42 billion active) and a 1 million-token context window, built for coding and agentic work. Meta says it runs on two Apple M5 Ultra Mac Studios using Apple's MLX framework. It is available through API platforms including Together AI, Groq and OpenRouter, and the weights are under the Muse Model License, which Meta says carries limited commercial terms.

• Read the Muse Model License on Meta's page before any business use, since Meta says the commercial terms are limited.
• If you want to try the model without buying hardware, ask your developer to test it through one of the API platforms Meta lists and compare cost against what you pay now.

Source: Meta AI Research. This is our short summary of their reporting. The paragraphs marked "Our read" and the things to do are SeedFoundry's opinion. The summary is drafted with AI tools. Image: Meta AI Research, from its own announcement. How we source and credit