SPDX license identifiers

Standardized short codes (AGPL-3.0, MIT, Apache-2.0) identifying a project's open-source license.

F-Droid attaches an SPDX identifier to every one of its 4,247 apps, making license-based filtering mechanical.

In this catalog it appears concretely: - f-droid-open-source-android-apps — "Apps are all free-software licenses ... with SPDX identifiers exposed per record". - sourceforge-software-directory — "hosted code must carry OSI-compliant licenses". - github-rest-api-repositories-search — "Repository content remains under whatever license each project declares (exposed in the license field)".

License language decides what you may ship to customers. Misreading it has ended product launches, and the gap between free to view and free to redistribute is where most of those failures begin.

The failure mode is concrete: a source can carry the SPDX license identifiers label while differing from what you need on exactly the dimension that matters — Apps are all free-software licenses ... with SPDX identifiers exposed per record. Comparing two sources on that line usually settles the choice faster than any feature matrix.

You rarely have to take a vendor's word for it. 82.4% of the 1,744 datasets Datadory catalogs are free to access, and f-droid-open-source-android-apps lets you inspect the real artifact before any budget is committed.

Treat every claim of this attribute as testable:

1. Open f-droid-open-source-android-apps and confirm its record — "Apps are all free-software licenses ... with SPDX identifiers exposed per record" — against the files you actually receive.
2. Open sourceforge-software-directory and confirm its record — "hosted code must carry OSI-compliant licenses" — against the files you actually receive.
3. Open github-rest-api-repositories-search and confirm its record — "Repository content remains under whatever license each project declares (exposed in the license field)" — against the files you actually receive.

See the term applied to real records: application-software data.

Adjacent concepts worth reading next: - commercial delivery terms database license - open source package registries - share alike license