Nvidia, Microsoft and other major technology companies are backing open-source AI models through a new public letter, according to multiple reports. The announcement adds to an ongoing debate over how open-source systems should be regulated compared with closed, proprietary models developed by companies such as OpenAI and Anthropic. The open-source approach generally makes model code and, in many cases, related components available to outside developers, which supporters say can encourage transparency, collaboration and broader innovation. Critics and regulators, however, raise concerns that open distribution can make it harder to control misuse, including the creation or deployment of harmful applications. The reports note that the letter comes amid wider scrutiny of AI safety, security and governance frameworks. While the signatories advocate for open-source development, the discussion also reflects differing views on whether current oversight mechanisms can effectively address risks associated with models that may be modified or redistributed outside of a single company’s control. The letter therefore highlights both the push for wider access to AI capabilities and the regulatory tension between openness and risk management.