**[Open-Source AI Petition Doubles in Two Days: OpenAI and Google Join, Anthropic Declines to Sign]** According to monitoring by Beating, the U.S. is currently discussing whether to impose restrictions on downloadable and self-deployable open-source models. Companies such as NVIDIA and Microsoft subsequently 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 grown from the initial 25 to 50 companies, with OpenAI, Google, AMD, Cloudflare, GitHub, and Cisco among those joining later. While OpenAI and Google rely on their closed-source flagship paid models like GPT and Gemini, they have also launched open models such as gpt-oss and Gemma, respectively. Signing the letter does not affect their ability to continue selling closed-source models but helps them maintain a stake in the open-model landscape. Anthropic has not signed the letter, which aligns with its current product and policy direction. The company 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 officially signed the letter. Elon Musk has publicly expressed support on X (formerly Twitter), but xAI does not appear on the official list of signatories. [Original Link]