Berkeley Professor Ion Stoica and his students don’t like being one-upped by anyone, let alone by archnemesis Stanford. That’s why, when a user asked for a way to compare their open-source chatbot Vicuna with the rival school’s Alpaca model, the #Berkeley team pitted the bots against each other in a bloody #AI battle. The user community went wild. Soon, Stoica’s group added the ability to test random models side by side and let people vote on the battle outcome. It was all in good fun, explains associate professor Joseph Gonzalez, who worked on the project along with Stoica and his students We-Lin Chiang and Anastasios N. Angelopoulos. Out of that fun came ChatBot Arena, a website that hosts over 400 AI models, allowing users to chat with multiple ones simultaneously. Rebranded as #LMArena in April, with Stoica serving as chairman, Chiang as CTO and Angelopoulos as CEO, the company has raised $100 million in VC funding at a $600 million valuation. The 2-year-old outfit is already bei...