It looks like they use java and sparql to put ontologies in a mongo database and then have an api to return terms and persons or organizations in the ontologies. Looks like there are 716 ontologies. The code is from 4 years ago so I don’t know how often or when they update the database, or if they look for new ontologies or if the list is never changed.
It would be great to have it updated in an adaptable way and the vocabs themselves be in a triple store on a pod or in SemApps. A dynamic cache of ontologies (or shapes or forms) that you could analyze or update in custom ways, and work on collaboratively.