Web-based Visualization of Ontologies
WebVOWL is a web application for the interactive visualization of ontologies. It implements the Visual Notation for OWL Ontologies (VOWL) by providing graphical depictions for elements of the Web Ontology Language (OWL) that are combined to a force-directed graph layout representing the ontology. Interaction techniques allow to explore the ontology and to customize the visualization. The VOWL visualizations are automatically generated from JSON files into which the ontologies need to be converted. A Java-based OWL2VOWL converter is provided along with WebVOWL.
Note that WebVOWL is able to visualize most language constructs of OWL 2 but not all of them yet (and also not all combinations). For instance, complex datatypes and some instance level constructs are not supported by WebVOWL at the moment.
A custom ontology can be visualized by opening the Ontology menu and either entering the IRI of the ontology or uploading the ontology file. The size of the ontology files that can be visualized is limited to 10MB in the public WebVOWL installation.
Note that converted ontologies are neither saved nor cached on the server. However, they are cached in the web browser to allow for a more fluent interaction. If you want to convert a custom ontology another time, simply hit the reload button of your web browser.
A custom ontology can also be visualized by appending its IRI to the URL of WebVOWL. For instance, the following URL requests the visualization of the FOAF vocabulary: Note that the dynamically generated visualizations will look different due to the force-directed layout. A stable VOWL visualization can be shared by exporting it to SVG or printing it as a PDF file. Alternatively, the generated JSON file can be exported and linked or uploaded. If the JSON file has been exported using WebVOWL, the VOWL visualization will be restored with the layout and user settings it had before. Here is again an example for the FOAF vocabulary: With this option, the VOWL visualization looks alomost the same whenever it is opened. Note that a different parameter is used in the URL of WebVOWL in this case («url» instead of «iri»). If the node positions and user settings are not of importance but the VOWL visualization should be reset whenever it is opened, simply link the JSON file generated by OWL2VOWL instead of the one exported from WebVOWL: Finally, custom settings can also be encoded directly in the URL.
