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information artifact ontology (IAO)

The Information Artifact Ontology (IAO) is a new ontology of information entities, originally driven by work by the OBI digital entity and realizable information entity branch.

The IAO mailing-list is available at


Version Filename PURL Link
Release iao.owl
Development iao-edit.owl

The development version IAO (iao-edit.owl) imports all ontologies/files needed for the full version of the IAO ontology:

OBO Metadata Ontology (OMO) was part of the IAO, developed in a separate OWL file. It contains metadata properties that have been widely used by many OBO Foundry ontologies. In early 2020, it was registered as an indepentent ontology. Please check the OBO Metadata Ontology (OMO) on the ontology-metadata repository.

A reasonable place to start browsing the IAO is at the terms information content entity or data item or the property is about.

Conference calls

IAO conference calls take place on an occasional basis, usually via Skype. Information about those is posted on our mailing-list, and agenda and minutes are available here. Anybody is welcome to join at any time.


The IAO is a descendant of the DENRIE branch of the OBI Project, edited by Chris Stoeckert and other IAO team members.

Presentations and Meetings

The first workshop on the IAO took place in Boston at the MIT Stata Center, June 9, 2008.

In July 2009, a tutorial From Basic Formal Ontology to the Information Artifact Ontology was presented, colocated at the ICBO: International Conference on Biomedical Ontology. Slides that include a section on topics in the IAO are here. Other presentations may be of interest.

In July 2011, a workshop was held co-located with ICBO, dealing with adverse event representation based on IAO and OGMS. See A working session was organized on Friday July 29th 2011.

In May 2012, a meeting discussing a signature discovery ontology, much of which was concerned with future development of IAO.

A working session on IAO was held on Saturday July 21st, 2012, 6-8pm during the ICBO 2012 conference.

Projects known to be using IAO

and as listed on IAO's BioPortal page: