The ATOM Report: Measuring the Open Language Model Ecosystem

TL;DR

This paper provides a detailed snapshot of the open language model ecosystem, highlighting adoption trends, regional shifts, and key metrics for leading models like Llama and Qwen.

Contribution

It offers the first comprehensive analysis of open language model adoption, regional dominance shifts, and ecosystem dynamics based on diverse data sources.

Findings

Chinese models overtook U.S. models in summer 2025

The ecosystem includes ~1.5K mainline open models

Analysis covers downloads, derivatives, market share, and performance

Abstract

We present a comprehensive adoption snapshot of the leading open language models and who is building them, focusing on the ~1.5K mainline open models from the likes of Alibaba's Qwen, DeepSeek, Meta's Llama, that are the foundation of an ecosystem crucial to researchers, entrepreneurs, and policy advisors. We document a clear trend where Chinese models overtook their counterparts built in the U.S. in the summer of 2025 and subsequently widened the gap over their western counterparts. We study a mix of Hugging Face downloads and model derivatives, inference market share, performance metrics and more to make a comprehensive picture of the ecosystem.