Microsoft, Nvidia, Meta and 22 others defended open weights. Anthropic and OpenAI didn’t sign.

A coalition of 25 groups, including Microsoft, Nvidia, and Meta, urged Washington not to rush new restrictions on open-weight AI.

The statement defended distillation as a legitimate technique, even as U.S. officials accused China’s Moonshot AI of using it to steal IP.

Startups and developers say open models are vital because they are cheaper to run than closed systems from Anthropic and OpenAI.

The debate could determine future access to low-cost open models and reshape the balance between open and closed AI ecosystems.