Meta Gave Away a Giant AI Model for Free — Muse Spark Open Has 816 Billion Settings and Can Run on Two Desk Macs

On Oct 15, 2026, Meta released Muse Spark Open: free downloadable weights for an 816-billion-parameter AI model. Think of those parameters as dials the AI tunes as it learns. Meta calls it the most capable US open-weight model to date. Meta and Apple say it can run locally on two Apple M5 Ultra Mac Studios, so the work stays on your machines instead of a cloud data centre. Only a slice of the model wakes up for each answer (about 42 billion of the 816 billion parameters), which is why that desk setup can hold it. A Mac Studio with the needed chip starts around $10,799, CNBC reports — and you need more than one. Corroborated by The Verge and Meta's own research post.