I remember using Actionscript to build some UI widgets for embedded devices and ... not hating it. The devices used proprietary level 7 protocol sitting on top

I remember using Actionscript to build some UI widgets for embedded devices and ... not hating it. The devices used proprietary level 7 protocol sitting on top of regular TCP/IP (could easily debug using netcat). Actionscript made it easy to work with this proprietary protocol. How would one do this with Javascript these days? You probably couldn't do it with WebSockets since WebSockets are at the same level 7 as the proprietary protocol, so you'd need to run some server to translate. Maybe, this https://www.w3.org/TR/raw-sockets/ https://www.w3.org/TR/raw-sockets/ ?