Comparison of WebKB with related tools

WebKB (WebKB-1 / WebKB-2) is a Knowledge Modelling (KM) tool, an Information Retrieval (IR) tool and an annotation tool. The following table was created in 1998 to compare the features of WebKB-1 with other tools in each of these three categories. The WebKB column was updated in 2003 to include the features of WebKB-2.

Table 1. Comparison of WebKB with other IR/KM/Annotation tools
("+" means that the tool supports the feature, "+(1)" that WebKB-1 supports it but not yet WebKB-2, "+(2)" that WebKB-2 supports it but not WebKB-1,  "~" that the support is limited, and "?" that not enough information has been found to decide if the tool supports the feature or not)
Shoe Onto-
Cue KSL Ika-
Document search&exploitation     +    +    +    +     +     +   +         +   +     +    +
    Web documents exploitation     +      +    +     +     +   +         +   +     +    ~
    Automatic indexation of files      +                   +      
    Web robot                       +   +    
    Cache        +    +       ?         +      
Warehouse  +(2)     +             +   +         +    +
    Knowledge storage  +(2)     +             +   +        
    Maximal knowledge integr.  +(2)                         
Knowledge modelling tool     +    +    +    +     +     +   +   +   +   +        
    Natural language analysis      +                        
    Graphical guiding interfaces     ~    +    ~         ?   +            
    Intuitive KRL     +    ~    +    +     ~       +   ~   ~        
    Logic-based KRL     +    ~    +       +       +   +   ~        
    Executable knowledge  +(1)          +       +            
    Consistency verifiable     ~    ~         ~       ~   ~          
    Completeness verifiable     +    +             +   +   +        
    Ontology easily extensible     +    +    +    +       +   +   +   +   +        
    Default ontology (library)     +               +   +   +        
        Task ontology and models     +               +            
        Top-level domain ontology     +               ~   +   +        
        Natural language ontology  +(2)                         
    Knowledge generation     +               ?            
    Knowledge mixable with DEs     +    ~      +     +     +   +              
Indexation of some DEs     +    +    +    +     +     +   +               +     +
    Indexation of any DE     +                          
Knowledge search language     +    +    +    +     +     ~   ?   +     ~        
    Large ontology exploitation  +(2)                         
    Indexed DE retrieval     +    +    +         ?              
Document generation language     +    +           ?           +    


Languages, ontologies and tools

Hypertext tools allowing to comment or index some parts of a document. In public-annotation tools, the comments are centralised in a warehouse.
Examples of Web-based public-annotation tools:
- ComMentor:
- HyperNews:
CYC A very large, multi-contextual knowledge base and its associated inference engine. CycL is the CYC Representation Language.
CGI Common Gateway Interface.
CGKAT Conceptual Graph Knowledge Acquisition Tool.
[ Martin, 1995] [ Martin & Alpay, 1996] [Martin, 1996]
CGs Conceptual Graphs (CGs).
CGs engines Workbenchs for Conceptual Graphs:
- CoGITo [ Haemmerlé, 1995]
- Peirce [ Ellis, 1995]:*/
- for other ones, see
DSI tools Distributed Systems Integration tools. Examples:
- AlephWeb:
- Carnot:
- Infomaster:
- Information Manifold:*/
- Hermes:
- SIMS:*/
- TSIMMIS: http://InfoLab.Stanford.EDU/tsimmis/tsimmis.html
HTML HyperText Markup Language.
IR tools Information Retrieval tools. Examples of knowledge-based IR tools are given in the next entry. Annotations tools (see above) are also IR tools.
Other examples of Web-based IR tools are:
- ht://Dig:
- Harvest:*/
- W3QS:
- WebLog:
- WebSQL:
IR&KR tools Information Retrieval tools exploiting knowledge representations. Metadata tools (see below) are such tools.
Examples of CG-based IR systems are:
- AI-Trader:*/
- RIME: see Kheirbek & Chiaramella (1995)
Java A language which code may be loaded and executed by some Web-browsers.
JavaScript A language mixable with HTML and interpretable by some Web-browsers.
KA tools Knowledge Acquisition tools. WebKB and CGKAT are KA tools. Ontology servers&editors (see below) are knowledge modelling tools and thus may be seen as restricted KA tools.
An extensive survey on old and recent KA tools (including Cue and Protégé) and their use of ontologies may be found in Heijst & al. (1996).
See also the archives of the Knowledge Acquisition Workshops:
KA2 The Knowledge Annotation Initiative of the KA Community.
KADS-II An Advanced and Comprehensive Methodology for Integrated KBS Development.
KRLs Knowledge Representation Languages. Examples:
- Knowledge Interchange Format (KIF):
- the KL-ONE family of KRLs:
- Concept Maps:*/ and
MacWeb A knowledge-based hypertext tool. See [Nanard & Nanard, 1993].
Metadata Knowledge representations in Web-accessible documents. Here are three entry points for this theme in the W3C site.
Design issues:
Metadata tools Tools exploiting metadata, generally for information retrieval. Examples:
- Ontobroker:
- RDF tools, RDF-like tools, WebKB (see the entries below)
Ontologies Set of formal terms, generally structured by semantic relations and accompanied by constraints and formal or informal definitions.

One view to allow knowledge sharing and reuse is to developp a set of ontologies which are minimal, precise and possibly alternative. See for example the ontologies developped by the Knowledge Systems Laboratory:

A more global or linguistic-oriented view is to group and interconnect various type of objects relevant to a domain into a single framework, generally around a "kind-of" hierarchy. The types may not have formal definitions or even natural language definitions. They are essentially place-holders for implicitely refered kinds of concepts or relations. Three kinds of those kinds of ontologies may be distinguished.
Web-accessible ontology editors or ontology warehouses. Examples:
- APECKS:*/ and
- Ikarus:*/
- KSL Ontology Server/Editor (also called "Ontolingua browser"):
- Ontosaurus:
- WebOnto:
RDF Resource Description Framework.
Older note on the underlying rationales:
RDF tools Tools for editing or exploiting knowledge in RDF. See the section "RDF Software and Projects" in
RDF-like tools Tools exploiting a language similar to RDF. Examples:
- Ontology Markup Language (OML):
- Conceptual Knowledge Markup Language (CKML): and
SGML Standard Generalized Markup Language.
URI/URL Uniform Resource Identifiers/Locators.
W3C Word Wide Web Consortium.
Warehouses Web-accessible databases where users can store and search information. Public-annotation tools use warehouses (see also the "KM tools" entry). Other examples are:
- AI-Trader:*/
- Aliweb:
Web Word Wide Web. and*/
Web robots Web robots/wanderers/crawlers/spiders. Databases, FAQs and articles about Web robots may be found in:*/
- Altavista:
- DR-LINK:*/
- Infoseek:
- Lycos:
- Yahoo!:
Note: MetaCrawler ( and Savvy Search (*/ are tools which call in parallel most of current Web indexes systems or other user-selected main information source providers (e.g. Usenet News, Software directories), and can integrate their results.
WebKB The WebKB set of tools.
WebKB-GE A Visual Editor for Canonical Conceptual Graphs.*/
See also Pollitt & al. (1998)
XML Extensible Markup Language., and

Definitions for the general AI terms we use may be found at
while the terms related to hypertext concepts or the Web Architecture are defined in the W3C glossary ( Ontology related definitions may be found at

Additionnal publications

B. Carbonneill & O. Haemmerlé. ROCK : Un système de Question/Réponse fondé sur le formalisme des Graphes Conceptuels. In Actes du 9eme congrès Reconnaissance des Formes et Intelligence Artificielle, pp 159-169, Paris, January 1994.  URL:

G. Ellis. Managing Complex Objects. Ph.D thesis, Queensland University (Department of Computer Sciences), Australia, 1995.  URL:*/

O. Haemmerlé. CoGITo: une plate-forme de développement de logiciels sur les graphes conceptuels. Ph.D thesis, Montpellier II University, France, January 1995.  URL:

G. van Heijst, A.Th. Schreiber & B.J. Wielinga. Using Explicit Ontologies in KBS Development. In the special Issue of IJHCS/HA (International Journal of Human-Computer Studies/Knowledge Acquisition) on "Using Explicit Ontologies in KBS Development", Fall 1996.  URL:*/

A. Kheirbek & Y. Chiaramella. Integrating Hypermedia and Information Retrieval with Conceptual Graphs. In Proceedings of HIM'95, Hypertext-Information Retrieval-Multimedia (Eds: R. Kuhlen & M. Rittberger), pp. 47-60, Konstanz, Germany, April 1995.  URL:

P. Martin. Using the WordNet Concept Catalog and a Relation Hierarchy for KA. In Proceedings of Peirce'95, 4th International Workshop on Peirce, Santa Cruz, California, August 18, 1995.  URL:

P. Martin & L. Alpay. Conceptual Structures and Structured Documents. In Proceedings of ICCS'96, 4th International Conference on Conceptual Structures (Eds: P.W. Eklund, G. Ellis and G.Mann), pp. 145-159, Springer Verlag, LNAI 1114, Sydney, Australia, August 19-22, 1996.  URL:

P. Martin. Exploitation de graphes conceptuels et de documents structurés et hypertextes pour l'acquisition de connaissances et la recherche d'informations. Ph.D thesis, University of Nice - Sophia Antipolis, France, October 14, 1996.  URL:

P. Martin. The WebKB set of tools: a common scheme for shared WWW Annotations, shared knowledge bases and information retrieval. In Proceedings of ICCS'97, 5th International Conference on Conceptual Structures (Eds: D. Lukose, H. Delugach, M. Keeler, L. Searle and J. Sowa), pp. 585-588, Springer Verlag, LNAI 1257, Seattle, August 4-8, 1997.  URL:

J. Nanard & M. Nanard. Should anchors be typed too ? An experiment with MacWeb. In Proceedings of HTX'93, 5th ACM Conference on Hypertext, pp. 51-62, ACM Press, Seattle, Novembre 1993.

S. Pollitt, A. Burrow and P. Eklund. WebKB-GE - A Graphical Editor for Canonical Conceptual Graphs. In Proceedings of ICCS'98, 6th International Conference on Conceptual Structures, (Eds: M.L. Mugnier and J.F. Sowa), Springer Verlag, LNAI 1453, pp 111-118, Montpellier, France, August 12-14, 1998.  URL:

V. Quint & I. Vatton. Combining Hypertext and Structured Documents in Grif. In Proceedings of ECHT'92 (Eds: D. Lucarella), pp. 23-32, ACM Press, Milan, December 1992.  URL:

Philippe A. MARTIN, Griffith University, School of Information Technology, Australia
E-mail: pm .@. phmartin dot info

Last modified: Sat May 30 03:02:53 PDT 1998