Hello Zackify, author here. That’s a great question. I haven’t used Apollo in depth (since I started building this before it’s existance.) But Apollo is an opinionated GraphQL framework that includes the data-transport layer.
Primus-GraphQL is less opinionated and just provides a GraphQL data-transport layer (client and server). Primus-GraphQL also offers a network-layer for Relay (an opinionated GraphQL client framework that works well with React).
Since it is built on top of Primus it allows flexibility with data-protocol layer - from socket.io, socksjs, websockets, or even a custom implementation.
Hope that answers your question. Let me know if you have more :-)
