The Open Database License (ODbL) is a copyleft ("Share Alike") license agreement intended to allow users to freely share, modify, and use a database while maintaining this same freedom for others.
ODbL is published by Open Data Commons, part of the Open Knowledge Foundation.
Notable uses
The OpenStreetMap (OSM) project completed the move from a Creative Commons license to ODbL in September 2012 in an attempt to have more legal security and a more specific license for databases rather than creative works.
Other projects using ODbL include OpenCorporates, Open Food Facts, and Paris OpenData.
References
Open Database License Wikipedia(Text) CC BY-SA