Meta says its new open-weight AI model rivals and in some cases outperforms Chinese equivalents. Meta says its new open-weight AI model rivals and in some cases outperforms Chinese equivalents. Meta releases Muse Spark Open, a new'open-weight' AI model Meta says Muse excels at'multi-step reasoning' and'complex software engineering' as it races to catch up to Chinese rivals Meta on Thursday launched a new open-weight AI model which it claims rivals, and in some cases outperforms, similar products from leading Chinese developers. Muse Spark Open "is the most capable US open-weight model to date," Meta's chief of AI Alexandr Wang wrote on X. Unlike so-called closed models - such as Anthropic's Claude or OpenAI's ChatGPT - developers can download the parameters, known as weights and biases, of an open-weight model and modify them.

In case there was still any doubt about Meta's commitment to open models, the company is open-sourcing Muse Spark with a new open-weight model called Muse Spark Open. The 800-billion parameter model was optimized for Apple Silicon, but you'll need a staggering 1TB of RAM to run it locally. Meta, which has said it believes the US should not allow Chinese labs to lead on open-source AI, calls Muse Spark Open "the most capable US open-weight model to date." Benchmarks released by the company suggest Meta's model outperforms two leading Chinese models, GLM 5.3 and Kimi K3, on agentic tasks and visual reasoning. It's also the first model optimized to run locally on Apple's M5 Ultra-equipped Mac Studio machines.