To view the OWL file:
1) Download and install Protege (https://protege.stanford.edu/products.php#desktop-protege)
2) Upload the OWL file into Protege
3) If needed, update the memory limit in Protege to open large OWL files (https://www.michaeldebellis.com/post/memory-management-with-protégé)
4) View and interact with the ChemFOnt ontology