WebVOWL: Web-based Visualization of Ontologies

VOWL Specification »

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.

Run WebVOWL »

Note that WebVOWL is able to visualize most language constructs of OWL 2 but not yet all of them (and also not all combinations). For instance, complex datatypes and some instance level constructs are not supported by WebVOWL at the moment.

Screenshot of WebVOWL

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 1MB in the public WebVOWL installation.

Screenshot of a detail of WebVOWL

Note that converted ontologies are not saved or 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.


Linking

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:

http://vowl.visualdataweb.de/webvowl/#iri=http://xmlns.com/foaf/0.1/

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:

http://visualdataweb.de/webvowl/#url=http://vowl.visualdataweb.org/webvowl/foaf.json

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 «uri»). 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:

http://visualdataweb.de/webvowl/#url=http://vowl.visualdataweb.org/webvowl/data/foaf.json


Installation

WebVOWL

To run WebVOWL on your machine, download and unpack the following ZIP file:

Download WebVOWL (version 1.0.3) ↓ (~170 KB)

Simply open the HTML file in the extracted folder to execute WebVOWL.

Note that the conversion of ontologies into the VOWL-JSON format is not part of WebVOWL, but requires an additional converter such as OWL2VOWL. See the template if you would like to edit an existing VOWL-JSON file or create your own.

OWL2VOWL

To run the OWL2VOWL converter on your machine, download and unpack the following ZIP file:

Download OWL2VOWL (beta 0.3.1) ↓ (~24 MB)

Execute the JAR file with the following command (where 'Ontology IRI' is the IRI of the ontology you would like to convert into the VOWL-JSON format):

java -jar owl2vowl.jar -iri "[Ontology IRI]"

For instance, the following command converts the FOAF vocabulary into the JSON file required for WebVOWL:

java -jar owl2vowl.jar -iri "http://xmlns.com/foaf/spec/"

The converter is based on the OWL API, which can handle various OWL formats (RDF/XML, OWL/XML, Turtle, etc.). It requires at least Java 8 and comes with a README file that lists further conversion modes.

OWL2VOWL + WebVOWL

There is also a WAR file containing a bundle of both OWL2VOWL and WebVOWL for easy deployment on a Tomcat server:

Download bundle (WebVOWL 1.0.3 + OWL2VOWL 0.3.1) ↓ (~25 MB)

If you do not use the bundled WAR, you need a server component that links WebVOWL with the OWL2VOWL converter (e.g., a simple PHP script).


Sources

The source code of WebVOWL and OWL2VOWL is publicly available on GitHub:


Releases

Release history of WebVOWL:


Demo Paper

Read more about WebVOWL in the following paper:

Lohmann, S.; Link, V.; Marbach, E.; Negru, S.: WebVOWL: Web-Based Visualization of Ontologies. Proceedings of EKAW 2014 Satellite Events, LNAI 8982, pp. 154-158, Springer, 2015. [BibTex]


License

WebVOWL and OWL2VOWL are both released under the MIT license.

Copyright (c) 2014-2017 Vincent Link, Steffen Lohmann, Eduard Marbach, Stefan Negru, Vitalis Wiens

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.