Command vs. FastChat

Overview

Command is Cohere's enterprise model family for agents, retrieval-augmented generation, multilingual work, and private deployment. Command A+ is the current open-weight generation.

Cohere develops enterprise language models with an emphasis on retrieval, citations, multilingual applications, tool use, and data sovereignty. Command A+, released in May 2026, is a 218B-parameter mixture-of-experts model with 25B active parameters. It supports text and image input, reasoning, agentic workflows, 48 languages, and private deployment under the Apache 2.0 license.

Initial release: 2021-11-15

Current generation: Command A+

Reference

https://cohere.com/command

Further Reading

• https://cohere.com/blog/command-a-plus

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/