Meta and Apple team up to bring open-weight AI to Mac with Muse Spark Open

Meta and Apple have teamed up for AI. The two companies have announced that they are bringing open-weight AI to Apple’s Mac Studio with Muse Spark Open. Muse Spark Open is Meta’s latest open-weight model with 800-billion parameters.Announcing the model, Mark Zuckerberg thanked Apple CEO John Ternus on X, along with a photo of the Muse mascot sitting beside a Mac. “Muse Spark Open -- weights releasing today -- runs great on new Mac Studios thanks to work with John Ternus and Apple,” he wrote. Mark Zuckerberg wrote on X. Ternus responded, congratulating Meta on the release. "Amazing to run a model of Muse Spark Open's calibre and scale this efficiently, right from your desk,” the Apple CEO wrote. “Mac Studio keeps pushing the boundaries of on-device AI!" John Ternus replied to Zuckerberg. An open-weight AI model can be downloaded and run locally. In the case of Muse Spark Open, Meta said it was “optimised” for Apple’s Mac Studio with the M5 Ultra chip. The partnership brings together two long-standing tech rivals that have repeatedly clashed in the past over issues such as privacy and advertising. Meta’s AI chief Alexandr Wang said the companies had worked together for several months, with former Apple executive and current Meta researcher Daniel Gross playing an important role. "We're excited for mommy and daddy to be playing nice again," Wang told Axios.Muse Spark Open can run on MacAs per the announcement, developers could run the Muse Spark Open model locally across two to four connected Mac Studios powered by Apple's M5 Ultra chips. Meta described Muse Spark Open as the most capable US-developed open-weight model released so far. Muse Spark Open has 816 billion total parameters, of which 42 billion are active, and a one-million-token context window. It uses a mixture-of-experts architecture and is designed for coding, long-duration agentic tasks, complex software engineering and multi-step reasoning. As per benchmarks shared by Meta, Muse Spark Open can match or outperform leading open-weight models such as Kimi K3 and GLM 5.3 in certain benchmarks. The model is part of Meta's Muse family of AI models.Apple's unified memory architecture allows the M5 Ultra's integrated graphics processor to use up to 512GB of memory in each Mac Studio. According to Meta, two connected machines can hold the entire model and operate with 1TB of unified memory. Apple’s Mac devices have gained popularity in recent years for those wanting to run AI models locally. It appears that Muse Spark Open may be targeting such users.Alexandr Wang said many powerful open-weight models were too large to run on most personal computers, but the memory available on Mac Studios made running Muse Spark Open practical. The model operates on the device rather than in the cloud, meaning Meta does not receive developers' prompts or information about how it is used. "Meta has no control or visibility to any of that," he added.According to Meta, the model went through additional safety training and met the release thresholds under its Meta Superintelligence Scaling Framework. The weights are being released under the Muse Model License, which permits many developers to use the model free under limited commercial terms.The collaboration follows years of tension between Apple and Meta. During Facebook's Cambridge Analytica scandal in 2018, then-Apple CEO Tim Cook said he would not have been in Zuckerberg's situation, prompting Zuckerberg to call the comment "extremely glib.” Their dispute intensified after Apple's 2021 privacy changes restricted advertising-related tracking, with Meta estimating in early 2022 that the changes would reduce its revenue that year by $10 billion.However, it seems that AI has brought the two companies together. Alexandr Wang claimed that Apple and Meta would continue competing in some areas, but added: "Where it makes sense to collaborate and partner, we want to be able to do so."- Ends