US tech billionaire Elon Musk’s artificial intelligence start-up xAI has open-sourced Grok 2.5, an earlier version of its model series, intensifying the global race to challenge China’s lead in making AI products freely available for anyone to use, modify and share. Musk said on social media platform X.com over the weekend that Grok 2.5, touted as the company’s “best model last year”, was uploaded to Hugging Face, the world’s largest open-source AI platform. He added that Grok 3 would become...