TooTallNate/Java-WebSocket

Simple to use, blazing fast and thoroughly tested WebSocket client and server for Node.js

Socket.IO server implemented on Java. Realtime java framework

WebSocket emulation - Javascript client

Package gorilla/websocket is a fast, well-tested and widely used WebSocket implementation for Go.

A simple and modern Java and Kotlin web framework

C++ websocket client/server library

Netty project - an event-driven asynchronous network application framework

Simple, secure & standards compliant web server for the most demanding of applications

Command-line client for WebSockets, like netcat (or curl) for ws:// with advanced socat-like functions