25 US tech firms including Microsoft and Nvidia call for open-weight AI models

25 US tech companies including Microsoft, Nvidia, IBM, and Meta have signed an open letter urging policymakers to support open-weight AI models. Drawing from the open-source software movement, the letter says open-weight models allow anyone to download, modify, and deploy them, lowering barriers to AI use and boosting market competition. It warns that closed models also have safety risks and that openness helps researchers find bugs and improve security. The letter also calls for distinguishing legal model distillation from illegal misuse to avoid over-regulation. Policymakers are advised to expand computing access and public research funding. Open-weight models let startups and universities build on advanced models without starting from scratch, helping AI spread across factories, hospitals, farms, and more, strengthening US tech leadership and sharing benefits broadly.