[Update: SpaceX Has Joined the Open Source Open Letter Signatories, Anthropic Still Absent] According to monitoring by Beating, companies such as NVIDIA, Microsoft, and Meta have jointly released the open letter *'Open Weights and U.S. AI Leadership,'* which continues to expand its list of signatories. The number of signing organizations has grown from the initial 25 to 77. Among them, SpaceX has garnered the most attention. Previously, Elon Musk only shared Jensen Huang's post on X, stating, 'Fully support, Jensen is right.' At that time, the company did not sign the letter, but now SpaceX has officially appeared on the list. The letter calls on the U.S. government not to prematurely restrict open-weight models that can be downloaded and deployed independently, and to differentiate between normal distillation and illegal extraction. Anthropic remains absent from the list. [Original Link]