Command-line client for WebSockets, like netcat (or curl)
Realtime application framework (Node.JS server)
An embedded web server
websocket and http client and server library, with TLS support
Network library for developing TCP/UDP/SSL/HTTP/WebSocket/MQTT client
A Socket.IO client library for Java
Whakerpy - A light web application framework
A Retrofit inspired WebSocket client for Kotlin, Java, and Android