Meta released Muse Spark Open on October 16, 2026, an open-weight model with 816 billion total and 42 billion active parameters and a 1 million token context window, built for coding and long-running agent work. Meta reported 61.8 on JobBench and 89.2 on MCP Atlas, but Artificial Analysis scored it 39, tied with DeepSeek V4-1 Flash and 7th among open models. The license carries limited commercial terms, and hosted-service sellers over $200M revenue require a separate agreement. Meta and Apple also revealed a collaboration to run the model locally by pairing two to four Mac Studios, with Apple updating its MLX toolkit; the full model needs a terabyte of memory, about $40,000 in hardware.