JerryScript is a lightweight JavaScript engine designed to bring the successof JavaScript to small IoT devices like lamps, thermometers, switches andsensors. This class of devices tends to use resource-constrainedmicrocontrollers which are too small to fit a large JavaScript engine like V8or JavaScriptCore. JerryScript is heavily optimized for low memory consumptionand runs on platforms with less than 64KB of RAM and less than 200KB of flashmemory. Despite the low footprint, JerryScript is a full-featured JavaScriptengine implementing the entire ECMAScript 5.1 standard. It is actively used inproduction and already runs on more than one million smartwatches! JerryScriptis an open source project and has been released under the Apache License 2.0.The talk will include a demo showing JavaScript code executing on top ofJerryScript on a resource-constrained microcontroller.