Meta launches Muse Spark Open, an open-weight AI model built for Macs

Meta is framing Muse Spark Open as the most capable open-weight model in the United States, a claim backed by evaluation results the company released on Thursday. Open-weight models let others inspect and modify the underlying model, a contrast with closed and proprietary systems that Meta says can be less cost-efficient and less transparent.

The launch is notable for where the model runs. Muse Spark Open was designed to work with Macs and run locally on Apple's computers, though the memory requirement of at least 1 terabyte of RAM puts local use out of reach for typical machines. Meta points to the Mac Studio with the M5 Ultra chip as the best fit, which suggests the target is professional desktop work rather than casual experimentation.

Meta says it already tested the model in practical settings. It paired Muse Spark Open with Muse Code, its AI coding terminal, and used it for coding fixes on a Mastodon client that included bug fixes, new features, and a full build. It also deployed the model to run DaVinci Resolve, the high-end video editing software, where it reviewed and cropped footage.