Meta shakes up the frontiers, open and closed
Meta's Muse Spark Open halves the gap between American and Chinese open-weight frontier models
“We've gone from the best American open models being largely irrelevant to consumers who require the cutting edge of performance, to them being behind but relevant.”— Nathan Lambert
Meta released Muse Spark Open, now the strongest American-made open-weight model by a significant margin, joined by Reflection's Beam and Mistral Large 4 to reverse a trend where 20+ Chinese open models were outperforming all Western alternatives. Nathan Lambert frames this as a structural shift: the American open-weight ecosystem has gone from irrelevant to competitive at the frontier. The move also reflects aggressive positioning, with Meta dropping weights before Reflection and Mistral could release their own, signaling intensifying competition even within the Western camp.