FastChat vs. Llama

Overview

FastChat is the open platform for training, serving, and evaluating LLM chatbots developed and maintained by LMSYS.

FastChat is an open-source library for training, serving, and evaluating LLM chat systems from LMSYS. It includes training and evaluation code, a model serving system, a Web GUI, and a finetuning pipeline, and is the de facto system for Vicuna as well as FastChat-T5. FastChat also includes the Chatbot Arena for benchmarking LLMs.

Initial release: 2023-04-28

Reference

https://github.com/lm-sys/FastChat

Further Reading

• https://chat.lmsys.org/
• https://lmsys.org/projects/

Overview

Llama is Meta's open-weight model family. Llama 4 was its last major generation; Meta's active assistant-model development has shifted to Muse.

Meta introduced LLaMA in February 2023, helping catalyze the modern open-weight model ecosystem. Llama 2 added commercial use and chat tuning, while the Llama 3 series improved scale, multilingual support, and instruction following. Llama 4, released in April 2025, introduced native multimodality and a mixture-of-experts architecture. Meta subsequently shifted its actively promoted assistant-model line to the proprietary Muse family, but Llama models remain widely used and deployed.

Initial release: 2023-02-24

Current generation: Llama 4

Reference

https://www.llama.com/

Further Reading

• https://arxiv.org/abs/2302.13971
• https://ai.meta.com/blog/llama-4-multimodal-intelligence/