Lightstreamer
Lightstreamer is a web-based asynchronous messaging project, implementing the WebSocket protocol, the Comet model, the push technology paradigm, and the real-time web practices. Origin. The first version of Lightstreamer was created at the end of 2000, as one of the first attempts to implement real-time data push to HTML pages without employing Java applets. The application domain driving most of the interest in push technology at that time was market data distribution for the financial services industry. In the following years, Lightstreamer was used within other application domains too, including aerospace telemetry, where NASA chose Lightstreamer  to push live telemetry data for the International Space Station. Architecture. The Lightstreamer Server is a high-performance engine that manages all the connections with the clients through the Internet. It integrates with the backend systems via custom adapters. The Data Adapter receives the real-time data flow from the data feed and injects it into the Lightstreamer Server. The Metadata Adapter has control over authentication, authorization, and quality of service. Lightstreamer Server is made up of three logical layers: