Web application
Ontology Viewer
Read an ontoterminology as a tree. Explore concepts, reveal their instances and share a standalone view.
The application opens in a new tab.
Illustrative structure · not a tool screenshot
Tool guide
Work with OTV
On this page
OTV is a read-only hierarchy viewer. Use it to inspect the conceptual structure of a compatible ontoterminology before exploring its full network in an RDF viewer.
Requirements
Use a current browser; no installation is required. Input must contain the OTV and OWL vocabularies. An arbitrary RDF file may not produce a tree.
Load a file
Choose “Upload a OTV/RDF file”. Check the reported concept and object counts. If both are zero, verify the file’s vocabulary and its export settings in TEDI.
Two views
isA shows concepts and their generic parents. isA + instanceOf adds the individuals instantiating those concepts. The second view can be substantially larger.
Navigate the tree
Use Zoom, Expand all, Collapse all, Rotate and Space controls to make the tree readable. Reset restores the default view. For large hierarchies, collapse everything and open one branch at a time.
Share a standalone view
“Generate standalone version” exports a self-contained, explorable copy of the current view. Share it with a colleague or alongside a dataset.
Troubleshooting
Empty tree: check OTV/OWL vocabulary. Missing individuals: switch to isA + instanceOf. Crowded display: collapse branches and adjust spacing or orientation.
Tool information
- Developer
- Christophe Roche
- Documented version
- 1.0
- Application
- Web application
- Formats
- OTV/RDF · OWL
Licence & citation
The supplied tool documentation specifies PolyForm Noncommercial 1.0.0. It permits use, modification and sharing for permitted non-commercial purposes, with the required licence and notices retained. It is source-available, with a non-commercial restriction. Check the licence included with the version you use.
Citation
Roche, C. (2025). OTV Ontology Viewer (1.0). TALOS AI4SSH Laboratory, University of Crete. https://tools.talos-lab.eu/OTV_Ontology_Viewer/Developed within TALOS AI4SSH, University of Crete, Horizon Europe grant agreement 101087269.
Visual sources
Logos and interface images are existing TALOS/tool-author assets, reused for this documentation. The screenshots show the documented interface; live versions may differ.