In this talk I will share my experience from building macchina.io, an open source toolkit forfor rapidly building IoT applicationsthat run on Linux-based devices like the Raspberry Pi, Beaglebone or RED Brick.It implements a modular, extensible JavaScript and C++ runtime environment inspired by OSGi,providing interfaces to various kinds of sensors and devices, as well as cloud services.macchina.io is based on the POCO C++ Libraries and the V8 JavaScript engine. I will first give a brief overview of the toolkit, then talk about some of the more interesting implementation details, like the C++-to-JavaScript bridging mechanism that allows the use of C++ classes from JavaScript without the need to manually write glue code or separate interface descriptions. I will also demonstrate how to build an IoT application that collects various sensormeasurements, stores them in a local database, visualizes them on a local website and performs various actions, such as sending SMS messages or posting to Twitter if certain eventsoccur, all with just a few lines of easily comprehensible JavaScript.