Chatbot Arena

The LMSYS crowdsourced pairwise leaderboard (ICML 2024) that became the industry's default human-preference evaluation — a joint Berkeley/Stanford effort (Zheng, Sheng, Stoica, Gonzalez et al.). In-window artifacts include VisionArena (CVPR 2025), Search Arena (ICLR 2026), RouteLLM, and Prompt-to-Leaderboard routing (#1 on the Arena via routing). The operation incorporated as LMArena in April 2025 ($100M seed; "Arena" rebrand and $150M Series A at $1.7B, Jan 2026) — post-incorporation output belongs to the company; the universities keep the original artifacts. Dated mid-window for the joint-era corpus.