ONNX
LF AI & Data (Linux Foundation)ONNX (Open Neural Network Exchange) is an open standard format and specification for representing machine learning models, defining an extensible computation graph model plus built-in operators and standard data types. It enables interoperability so models can move between frameworks like PyTorch, TensorFlow, and scikit-learn. It is governed under the Linux Foundation as part of LF AI & Data.
Verified live 2026-06-22 via primary sources. Apache-2.0 license body confirmed; full source public on GitHub.
Openness
5 high confidence- license
- Apache-2.0(OSI)
- source
- public
- core-gated
- ungated
Apache-2.0 license body confirmed; full source public on GitHub.
- https://github.com/onnx/onnx/blob/main/LICENSE recorded 2026-06-22
Apache License Version 2.0 full text
Adoption
5 high confidenceRe-scored 4->5. 20.65M PyPI downloads in the last 30 days. The map's prevailing usage_volume level-5 floor is >10M/mo (cf. pydantic-ai ~31M, llama-index ~10.18M at level 5; the companion onnxruntime is already level 5 at ~74.7M); the prior level 4 applied the stricter ml_frameworks-batch band. ONNX is the de facto cross-framework model-exchange standard and clears the floor.
- https://pepy.tech/projects/onnx recorded 2026-06-25
20,653,241 downloads in last 30 days
Capability
5 high confidenceDefines the graph model, operators, and data types used as the de-facto interchange standard.
- https://github.com/onnx/onnx recorded 2026-06-22
README: open format with extensible computation graph, built-in operators
Unchanged since 2026-07-30 (last edited, not re-checked)