Muse Spark Open
Meta released the weights for Muse Spark Open, described as the most capable US open-weight model to date, with 816B total parameters (42B active) and a 1M-token context window. The natively multimodal model is built for coding and long-horizon agentic work and can run locally on Apple M5 Ultra Mac Studios.
Why it matters A frontier-scale open-weight release from a major US lab narrows the gap between proprietary and open models and gives developers, researchers, and smaller companies access to agentic-grade capability without API lock-in. Running a model of this scale on consumer-adjacent hardware (Mac Studio) also signals a shift toward local/on-device frontier inference, with implications for privacy-sensitive enterprise deployment and competitive pressure on closed-model providers.
What to watch Watch for independent benchmarking against closed frontier models and reaction from Chinese open-weight labs competing in the same class.