openHAB - "empowering the smart home" - vendor and technology agnostic open source home automation
ReachOut - ReachOut is a field service management suite to streamline field processes with customizable mobile-based forms and workflow.
Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
DeltaSalesApp - Field Sales Force Automation & Field Force Tracking Software
ioBroker - flexible and modular application for the IoT and Smarthome
Smart Service - Smart Service's QuickBooks integration makes it the ultimate scheduling and dispatch software for HVAC, plumbing, pest control, and other service industries.