There are 4 repositories under ontology-visualization topic.
A simple ontology and RDF visualization tool.
An interactive radial tree for functional hierarchies and omics data visualization
The sample web app for the yFiles use case about an Ontology Visualizer.
An Ontology Visualization & Authoring Workbench for KRSS-Based Description Logic & OWL Reasoners
Schema for configurations / stylesheets for visualizing ontology and KGs
An otology has been built for the actual need of moving from the relational database to Graph-based database.
Web shell for presentation and analysis of Ontologies based on Controlled Natural Language