The ontology languages RDFS and OWL lack practical documentation support. We present the mathematical markup language OMDoc as a tool for documenting Semantic Web ontologies.

The semantic web ontology languages RDFS and OWL are
widely used but limited in both their expressivity and their support for
modularity and integrated documentation. Expressivity, modularity, and
documentation of formal knowledge have always been important issues
in the MKM community. Therefore, we try to improve these ontology
languages by well-tried MKM techniques.

Concretely, we propose embedding the language concepts into OMDoc
to make use of its modularity and documentation infrastructure. We show
how OMDoc can be made compatible with semantic web ontology lan-

As the semantic web ontology languages RDFS and OWL are limited in
both their expressivity and their support for modularity and documentation,
we propose the mathematical markup language OMDoc as an alternative.
We show how OMDoc can be made compatible with semantic web ontology
languages, focusing on knowledge representation, modular design, documentation, and metadata. We evaluate our technology by re-implementing the
FOAF ontology and applying it in a novel metadata framework for technical
documents (including ontologies).

In this chapter, we present the SWiM system, a prototype semantic wiki for collaboratively building,
editing, and browsing mathematical knowledge. SWiM is based on the semantic wiki IkeWiki, but re-
places the wiki text with OMDOc, a markup format and ontology language for mathematical documents
as the underlying knowledge representation format. Our long-term objective is to evolve SWiM into an
integrated platform for ontology-based added-value services. As a social semantic work environment, it