This document was originally posted on 8/1/2013.
Rocket is a technique for building real-time functionality on top of REST web services that leverages web standards like [Server-Sent Events][SSE] and [JSON Patch][RFC6902]. Most importantly, it fits comfortably with how you're already building applications.
Just as light can act as both a particle and a wave, so information can be thought as both a document and a stream.
Each approach has its particular strengths and weaknesses: