Meta releases open-weight Muse Glimmer model, keeps Muse Spark closed

Meta is back in the open-weight business. Sort of. On August 10, 2026, Meta Platforms released Muse Glimmer, an AI model that developers can download, modify and run on their own hardware. The company’s most capable system, Muse Spark, stays closed and is available only through an API or paid access. What Meta actually released Muse Glimmer has approximately 30 billion parameters. Parameters are the internal settings a model learns during training. More of them usually means more capability, along with heavier hardware demands. The headline feature is where Glimmer runs. Meta says it works locally on consumer machines, such as a Mac or a PC with a single graphics card. You don’t need a data center or a cloud bill to use it. Meta built Glimmer for local, agentic work. “Agentic” means the model takes actions for you, not just answers questions. Meta points to tasks like managing calendars, files and messages. Muse Spark sits on the other side of the wall. It remains Meta’s more advanced model, and it stays proprietary for now. Outsiders can rent its capabilities, but they can’t look under the hood. That wall may get a door soon. Meta plans to release open weights for a version of Spa...