Communication JavaScript application (client) and a Julia application (server)

Isn’t it all here? Julia Web · GitHub

Julia can work as a web server for you, for Genie.jl (or use external web server).

Possibly this one helps GitHub - wookay/Bukdu.jl: Bukdu 🌌 is a web development framework for Julia and JuliaWebAPI.jl (e.g. ZMQTransport or JSONMsgFormat?), WebSockets.jl, WebIO.jl (with example) and GitHub - JuliaGizmos/JSExpr.jl: Translate Julia to JavaScript