We have opened a feature request with Apollo (https://www.apollographql.com) for an Apollo Server (GraphQL) in Rust Lang.
Right now Apollo say not many people have asked them for this (yet!!!), so if you would love Apollo Server (GraphQL) in rust please add your interest at (Official) Apollo Server in rust · Discussion #292 · apollographql/apollo-rs · GitHub
Perhaps Apollo and juniper could collaborate...
Thanks!