LMSYS Org

The Large Model Systems Organization (LMSYS Org) is an organization focused on developing large models and systems that are open, accessible, and scalable. Its work spans the tools and platforms needed to train, serve, and evaluate large language models and multimodal models, alongside research into their performance, reliability, and efficient operation. LMSYS Org’s projects include SGLang, a high-performance serving engine; FastChat, an open platform for training, fine-tuning, serving, and evaluating chatbot models; and RouteLLM, a framework for serving and evaluating language-model routers.

Its portfolio also includes Chatbot Arena, which compares language models through anonymous, randomized, crowdsourced battles, and Vicuna, an open-source chatbot. The organization shares technical updates and research through its blog, covering topics such as agent training, serving security, and reinforcement learning. With more than 15 projects, a large community of contributors, and support from industry and research partners, LMSYS Org works to make advanced AI systems more practical and widely accessible