Some top-level ontologies
 

Here we list some kind-of hierarchies of first order types.
We do not address ontologies which are theories such as
the ontologies of KSL (Stanford).

Concept type top-level ontologies
The first two levels of the WordNet 1.5 ontology of noun meanings
(the WordNet 1.5 ontology organizes 90.000 conceptual categories)
The WordNet 1.5 top-level ontology integrated in a situation data model
(-> this top-level ontology plus WordNet may be used for guiding knowledge representation
    (this is the ontology provided by default in our knowledge acquisition tool CGKAT))
The Situation Data Model of Tepfenhart (1992)
Sowa's top-level ontology for concept types (from a paper given at ICCS'95)
The concept type hierarchy of the Generalized Upper Model
The top-level concept type hierarchy of Mikrokosmos

Relation type top-level ontologies 
The top-level relation type hierarchy proposed by CGKAT
The relation type hierarchy of the Generalized Upper Model
The top-level relation type hierarchy of Mikrokosmos



Ontology: A Resource Page
IKARUS: a WWW accessible knowledge management system (some ontologies are provided)
A WWW accessible prototype for WordNet 1.6, the multi-language WordNet (Netscape 2.0 required)