I don't have much experience using GraphQL. Is it a fun language to use? I wonder if we should provide a GraphQL API to PLDB.
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.