Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
Mapbox - An open source mapping platform for custom designed maps. Our APIs and SDKs are the building blocks to integrate location into any mobile or web app.
ioBroker - flexible and modular application for the IoT and Smarthome
QGIS - QGIS is a desktop geographic information system, or GIS.
openHAB - "empowering the smart home" - vendor and technology agnostic open source home automation
OpenStreetMap - OpenStreetMap is a map of the world, created by people like you and free to use under an open license.