Open Source AI Coalition Doubles in Two Days: OpenAI and Google Join, Anthropic Does Not Sign

According to Dynamic Beating monitoring, the United States is discussing whether to restrict the downloading and self-deployment of open-source models. Subsequently, companies such as NVIDIA and Microsoft released an open letter titled "Open Weights and U.S. AI Leadership," urging the government not to impose premature restrictions. The list of signatories has expanded from the initial 25 companies to 50, with later additions including OpenAI, Google, AMD, Cloudflare, GitHub, and Cisco, among others.

Although OpenAI and Google rely on flagship closed-source models like GPT and Gemini for revenue, they have also respectively introduced the gpt-oss and Gemma open models. Signing the letter will not prevent them from continuing to sell closed-source models but will help them maintain the credibility of open models.

Anthropic chose not to sign, aligning with its current product and policy trajectory. As it does not offer open-weight products like gpt-oss or Gemma, and has recently emphasized the risks of illegal distillation and model leakage.

Additionally, Amazon/AWS, Apple, and xAI have not formally signed. Musk has only expressed public support on X, and xAI is not listed on the official roster.