The WebSockets technology promises to fill a niche in web applications by enabling browsers and servers to exchange messages with high frequency, low latency and low bandwith requirements in full duplex mode. The WebSocket protocol is an IETF standard, the WebSocket API is almost standardized by the W3C, and the JSR-356 will deliver a Java API in Java EE 7. There are already implementations in node.js and in a number of Servlet containers and Java frameworks. The time is as good as ever to start digging into it and there is so much to consider — from getting familiar with the protocol and the API, to sorting through the choices on the browser and on the server side, practical challenges with browser support and network issues, and so on. Furthermore, WebSockets offer a messaging-style architecture that’s in sharp contrast to the RESTful architectures that connect the web today, so learning where to draw the line will be essential.