From DT Online
Node-RED is a programming tool for wiring together hardware devices, APIs and online services in new and interesting ways. It provides a browser-based editor that makes it easy to wire together flows using the wide range of nodes in the palette that can be deployed to its runtime in a single-click.
Features and Applications
Node-RED is a flow-based programming tool which started life in early 2013 as a side-project by Nick O’Leary and Dave Conway-Jones of IBM’s Emerging Technology Services team and now a part of the JS Foundation.
Invented by J. Paul Morrison in the 1970s, flow-based programming is a way of describing an application’s behavior as a network of black-boxes, or nodes as they are called in Node-RED. Each node has a well-defined purpose; it is given some data, it does something with that data and then it passes that data on. The network is responsible for the flow of data between the nodes.
A series of tutorials with full explanations of many of the Node RED features can be viewed here on YouTube