Wikipedia
Omeka is a free, open source content management system for online digital collections. As a web application, it allows users to publish and exhibit cultural heritage objects, and extend its functionality with themes and plugins. A lightweight solution in comparison to traditional institutional repository software like DSpace and Fedora, Omeka has a focus on display and uses an unqualified Dublin Core metadata standard.
Its software is currently being used by the New York Public Library, the Newberry Library, as well as many small museums and historical societies. The Missouri School of Journalism uses Omeka to share their archive of 38,000 photographs from the Pictures of the Year International contest.
Developed by the Roy Rosenzweig Center for History and New Media at George Mason University, Omeka was awarded a technology collaboration award by the Andrew Mellon Foundation and is used to teach curation.