openHAB - "empowering the smart home" - vendor and technology agnostic open source home automation

Buddy Ohm - Buddy Ohm application

ioBroker - flexible and modular application for the IoT and Smarthome

The Thing System - The Thing System is an open source IoT platform.

Domoticz - Domoticz is a lightweight Home Automation System

BuildingOS - Our building energy management system and building management software centralizes building data and improves energy efficiency for reduced energy costs. Lucid is the leading software platform for managing building performance