The Team
Note: This SHOE web site is no longer being actively maintained. Work at the University of Maryland on web ontologies continues in the Semantic Web and Agents Project , which uses the Web Ontology Languages OWL and DAML+OIL. These languages are results of standardization efforts that are in part based on SHOE ( Jim Hendler is coChair of the Web Ontology Working Group sponsored by the World Wide Web Consortium.
Jeff Heflin and Sean Luke are now faculty members at Lehigh University and George Mason University, respectively. Like Dr. Hendler, Dr. Heflin is exploring the use of DAML+OIL and OWL, but is also continuing to build tools for SHOE as well. Information about his research and the latest SHOE developments can be found here.


Parallel Understanding Systems Group
Department of Computer Science
University of Maryland at College Park

SHOE is a small extension to HTML which allows web page authors to annotate their web documents with machine-readable knowledge. SHOE makes real intelligent agent software on the web possible.

HTML was never meant for computer consumption; its function is for displaying data for humans to read. The "knowledge" on a web page is in a human-readable language (usually English), laid out with tables and graphics and frames in ways that we as humans comprehend visually.

Unfortunately, intelligent agents aren't human. Even with state-of-the-art natural language technology, getting a computer to read and understand web documents is very difficult. This makes it very difficult to create an intelligent agent that can wander the web on its own, reading and comprehending web pages as it goes.

SHOE eliminates this problem by making it possible for web pages to include knowledge that intelligent agents can actually read.


* What's New? If you've visited this site before, you may wish to check here for a list of the latest changes.
* The SHOE FAQ. Answers to all your questions about SHOE. You may want to skim this before you delve into the specification.
* A SHOE Tutorial. A walk through SHOE, showing how to build ontologies, and annotate web documents using those ontologies.

Applications and Demos

* Semantic Search. This is the first SHOE search engine. It uses the SHOE Search tool as a query interface to a growing repository of SHOE pages. You can even validate and submit your own SHOE pages!
* The Knowledge Annotator. The Knowledge Annotator is a Java program which allows you to annotate your web pages with SHOE graphically, without having to muck about with HTML.
* Exposé This is a web robot written in Java which searches out web pages with SHOE entries, gathers the associated knowledge, and loads it into PARKA, U Maryland's high-speed knowledge representation system.
* PIQ (Parka Interface for Queries) A Java tool that allows you to visually query the SHOE information that has been discovered by Exposé.
* SHOE Search Another Java tool that allows you to query SHOE information that has been discovered by Exposé. Whereas PIQ is intended for expert users, SHOE Search is intended for the casual user. As such, it is much easier to use, but does not allow some of the more complicated queries that can be constructed in the PIQ.

The SHOE Specification

* The SHOE Specification. This specification gives the up-to-date definition of SHOE as a superset of HTML.
* Base Ontology. When it's been formalized, this will be the accepted "parent" ontology for all SHOE ontologies on the web.
* The SHOE SGML DTD. This gives the formal syntax of SHOE as an SGML application and extension of HTML.
* The SHOE XML DTD. This gives the formal syntax of SHOE as an XML application. For more information on creating valid XML SHOE documents, see the SHOE FAQ.


To see more information on any publication, including its abstract and citation, click on its title. To open a publication, click on the desired format. To see the whole list of PLUS publications, click here.

* Towards the Semantic Web: Knowledge Representation in a Dynamic Distributed Environment, by Jeff Heflin. Ph.D. Thesis, University of Maryland, College Park, 2001.
* A Portrait of the Semantic Web in Action, by Jeff Heflin and James Hendler. IEEE Intelligent Systems, 16(2), 2001.
* Semantic Interoperability on the Web, by Jeff Heflin and James Hendler. In Proceedings of Extreme Markup Languages 2000. 2000. Formats: PostScript, PDF.
* Dynamic Ontologies on the Web, by Jeff Heflin and James Hendler. In Proceedings of 17th National Conference on Artificial Intelligence(AAAI-2000). 2000. Formats: PostScript, PDF.
* Searching the Web with SHOE, by Jeff Heflin and James Hendler. In AAAI-2000 Workshop on AI for Web Search. 2000. Formats: PostScript, PDF.
* SHOE: A Knowledge Representation Language for Internet Applications, by Jeff Heflin, James Hendler, and Sean Luke. Technical Report CS-TR-4078 (UMIACS TR-99-71). 1999. Formats: PostScript, PDF.
* Coping with Changing Ontologies in a Distributed Environment, by Jeff Heflin, James Hendler, and Sean Luke. In AAAI-99 Workshop on Ontology Management. 1999. Formats: PostScript, PDF.
* Applying Ontology to the Web: A Case Study, by Jeff Heflin, James Hendler, and Sean Luke. In International Work-Conference on Artificial and Natural Neural Networks, IWANN'99. 1999. Formats: PostScript, PDF.
* Reading Between the Lines: Using SHOE to Discover Implicit Knowledge from the Web, by Jeff Heflin, James Hendler, and Sean Luke. In AAAI-98 Workshop on AI and Information Integration. 1998. Formats: PostScript.
* Ontology-based Web Agents, by Sean Luke, Lee Spector, David Rager, and James Hendler. In Proceedings of First International Conference on Autonomous Agents 1997, AA-97. Formats: PostScript, Gzipped PostScript (.ps.gz).
* Web Agents That Work, by Sean Luke and James Hendler. In IEEE Multimedia, 4(3), 1997. Formats: Gzipped Postscript, Gzipped Postscript without Figures 1 through 3, Postscript without Figures 1 through 3
* Ontology-Based Knowledge Discovery on the World-Wide Web, by Sean Luke, Lee Spector, and David Rager. In AAAI96 Workshop on Internet-based Information Systems. Formats: HTML, PostScript, Gzipped PostScript (.ps.gz).


* SHOE Ontologies. This page provides descriptions and links to SHOE ontologies that we have developed.
* Example Pages. We have annotated a number of pages within our group, as well as pages for the University of Maryland and other universities.
* Downloads. Many of the SHOE programs and libraries are now available for you to download.
* SHOE Image Links. If your web page uses SHOE, show it!
* SHOE and DAML. As a service to users of DAML we provide a number of the SHOE ontologies and content documents in DAML format.

The SHOE Team

Web Accessibility