W3C Technology and Society Domain The Semantic Web Home Page


Easy Access to the Semantic Web

In the fall of 2004, the Ontaria project was put on indefinite hold, as rule standardization (cf RIF) became a higher priority.

About Ontaria


Ontaria is a searchable and browsable directory of semantic web data. Our focus is RDF vocabularies with OWL ontologies, but all the RDF data we index is visible. The site is primarily intended for people creating RDF content who want to better understand which vocabularies are available and how they are being used. Beyond this, Ontaria may be useful for finding and exploring arbitrary RDF content.

Like most web directories and search engines, Ontaria gathers its information from other web sites, which it learns about via links and submissions.

Ontaria began as a project of W3C Semantic Web Advanced Development and moved to the Decentralized Information Group as part of a re-organization. It has been funded by DARPA's DAML program. Principal Investigator: Tim Berners-Lee. Lead Developer: Sandro Hawke.


Ontaria is an installation of SemWalker. ("Ontaria" refers to a web-based service offered by the W3C; "SemWalker" refers to the software used to offer that service. The Ontaria installation is customized for browsing ontology data.)

SemWalker is open source, available under the W3C license, from our CVS repository. It's a little early for anyone else to seriously try using the code, but it's there.


Ontaria is a service of the W3C, managed under the Semantic Web activity.

Ontaria is funded by the DARPA DAML program.

Ontaria development centers at MIT CSAIL, in new Stata Center.

Ontaria harvests, processes, and displays RDF information.

Ontaria is mostly written in SWI Prolog

Ontaria, while being mostly portable, happens to run nicely on Debian Linux.

Ontaria has been happily inspired at times by SchemaWeb. Imitation is the sincerest form of flattery.

Ontaria LogoThe Ontaria Icons were contributed by Scott Lefton.

Thanks to a Dougles Bowman article at A List Apart for CSS-happy tabs

Sandro Hawke, W3C
$Id: Overview.html,v 1.5 2009/07/06 23:42:58 sandro Exp $