Open Database License (ODbL)

The Open Database License (ODbL) is a copyleft license from Open Data Commons that grants reuse rights to a database under attribution and share-alike conditions, written specifically for databases rather than adapted from a creative-works license. Version 1.0, published June 2009, remains the current and only released version.

Why databases needed a license of their own

Standard copyright licenses, including the Creative Commons suite, were written to license copyrightable creative works — text, images, music. A database is a different kind of object: its individual factual contents (a coordinate, a measurement, a name) are frequently not copyrightable at all, while the selection, arrangement, or structure of the database may be. Complicating this further, some jurisdictions — most notably the European Union, under its Database Directive — also recognize a separate sui generis database right, protecting the investment made in compiling a database even where no copyright applies to its contents. ODbL was drafted to address all three layers at once: it separately licenses the database (the copyrightable selection/arrangement/structure), its contents (to the extent individual elements are protected), and, where a jurisdiction recognizes it, the sui generis database right. This is the core reason a generic CC license is a poor fit for a dataset and ODbL exists as a purpose-built alternative.

The three ODbL conditions

• Attribution. Public use of the database, or of works produced from it, must credit the source in the manner the license (or an accompanying ODbL-compliant notice) specifies.
• Share-Alike. If an adapted (modified) version of the database is publicly used, that adapted database must also be offered under ODbL — the copyleft mechanism that keeps derivative databases open.
• Keep Open. A redistributor may apply technological restrictions (such as DRM) to a copy, but only if an unrestricted version is also made available — a technological measure cannot be used to functionally revoke the license’s openness.

Note what ODbL’s share-alike condition does not require: producing a normal analytical or creative work from an ODbL-licensed database (a report, a map image, a chart) does not generally obligate that output itself to be ODbL-licensed, only an adapted database made public. This distinction between “database” and “work produced from a database” is specific to ODbL’s structure and is a common point of confusion for researchers reusing ODbL data.

The Open Data Commons license family

ODbL is one of three legal tools Open Data Commons publishes for data, forming a permissiveness spectrum comparable in spirit to the Creative Commons suite:

• PDDL (Public Domain Dedication and License) — dedicates a database to the public domain, with no conditions at all.
• ODC-BY (Attribution License) — requires attribution only, no share-alike.
• ODbL (Open Database License) — attribution plus share-alike, the most restrictive of the three, described above.

ODbL vs. Creative Commons licenses

Researchers and data managers choosing between ODbL and a Creative Commons license such as CC BY-SA for a dataset should weigh two practical differences. First, ODbL is drafted around database-specific legal concepts (database rights, the database/contents/work-produced-from-database distinction) that CC licenses do not address, giving it more precise legal footing in jurisdictions that recognize a sui generis database right. Second, because CC BY-SA’s share-alike condition is not written with database structure in mind, applying it to a dataset can create ambiguity about whether merging or subsetting the data counts as an “adaptation” requiring share-alike — a question ODbL’s drafting addresses more directly. In practice, many research data repositories default to open data released under CC0 or CC BY rather than a share-alike license at all, since NC/SA/ND-style conditions can interact poorly with how datasets get merged, subsetted, or recombined; ODbL is chosen specifically when a data publisher wants copyleft protection (derivatives must stay open) and views a database-specific instrument as more appropriate than adapting a CC license to that purpose. See CASRAI’s Data Management Plan (DMP) entry for where a dataset’s license is typically documented, and the reuse license entry for the general concept ODbL is one instance of.

Worked example

The best-known real-world ODbL adoption is OpenStreetMap, the collaboratively built geographic database, which relicensed its data from CC BY-SA to ODbL in September 2012 specifically because ODbL was purpose-built for database rights rather than adapted from a creative-works license. Any research project incorporating OpenStreetMap data must comply with ODbL’s attribution and share-alike terms for that geographic database.

Counter-example: a research dataset released under a plain “CC BY-SA 4.0” statement, with no reference to database rights or ODbL, is licensed under Creative Commons terms, not ODbL — the two are related in spirit (both are attribution-plus-share-alike copyleft instruments) but are legally distinct licenses with different drafting, and a data reuser must check which one actually applies rather than assuming they are interchangeable.

Related terms

See also: Creative Commons License, Open data, Reuse license, Data Management Plan (DMP), Licence, and Copyright.