WebSockets: Writing the Server

Part 3 of a series on WebSockets, walking through building a Node.js WebSocket chat server. Covers attaching a WebSocket server to an existing HTTP server, handling connection requests with origin whitelisting and protocol validation, managing a connection list using TCP socket properties as unique keys, and processing chat protocol messages (join, message, leave) with a broadcast function that relays messages to all connected clients. Includes practical code snippets and discussion of design decisions like connection identification and username tracking.