OpenML

license

BSD-3-Clause(OSI)

source

public(github.com/openml/OpenML)

core features withheld

no — community project represented by the not-for-profit Open Machine Learning Foundation

The server behind openml.org is published under BSD-3-Clause, and so is the rewrite that will replace it. OpenML is a community project backed by a not-for-profit foundation, with no paid edition.

• https://docs.openml.org/intro/Governance/ recorded 2026-10-07

  "The Open Machine Learning Foundation is a not-for-profit organization supporting, but not controlling, the OpenML project."

• https://raw.githubusercontent.com/openml/OpenML/HEAD/LICENSE recorded 2026-10-07

  "BSD 3-Clause License. Copyright (c) 2014-2021, OpenML."

• https://raw.githubusercontent.com/openml/OpenML/HEAD/README.md recorded 2026-10-07

  "This repository is in maintenance-only mode. We're phasing out the PHP-based REST API in favor of a much more modern FastAPI-based API."

• https://raw.githubusercontent.com/openml/server-api/HEAD/LICENSE recorded 2026-10-07

  "BSD 3-Clause License. Copyright (c) 2023, OpenML" for the Python server rewrite.

OpenML publishes no total of downloads or users, and its search index refused automated queries. Downloads of the openml client packages would count a client rather than the platform, so no reading was recorded.

• https://www.openml.org/api/v1/json/data/list/limit/5 recorded 2026-10-07

  The dataset listing API returns per-dataset status, format and data qualities; it carries no download or user counts.

Anyone can upload a dataset from a dataframe, and OpenML stores it in one uniform format, computes its characteristics and serves it back by ID to Python, R and Java. Tasks and benchmark suites are defined on top of the datasets, so the catalog also records how each one is used for evaluation.

• https://docs.openml.org/concepts/data/ recorded 2026-10-07

  "You can upload and download datasets through the website or though the APIs"; "OpenML assigns incremental version numbers per upload with the same name"; "OpenML will automatically analyze the data and compute a range of data quality characteristics".

• https://raw.githubusercontent.com/openml/server-api/HEAD/README.md recorded 2026-10-07

  "If you simply want to access data stored on OpenML in a programmatic way, please have a look at connector packages in Python, Java, or R."

• https://www.openml.org/api/v1/json/data/61 recorded 2026-10-07

  Dataset 61 (iris): "version":"1", "format":"ARFF", a "parquet_url" on data.openml.org and a default target attribute.