struct-ure/kg is a self-contained knowledge graph of tech skills and IT stuff (software, platforms, etc.). It presents a GraphQL API to retrieve information from the graph. Transparent management of the structure and content of the graph is accomplished using git. "Editing" the KG is as simple as making changes to directories and files.
I don't know about "fun", but it does offer some advantages over REST and others. I built struct-ure/kg on top of Dgraph, which auto-generates a GraphQL API from a schema definition. You should look into that if you decide to offer a GraphQL API.
As for PLDB, I'm impressed. That's a lot of data on programming languages! struct-ure/kg is designed to encompass all sorts of IT stuff. If you'd like to contribute to building out the "programming languages" sub-graph, I'd definitely welcome the help.