ifttt - IFTTT puts the internet to work for you. Create simple connections between the products you use every day.
Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
Make.com - Tool for workflow automation (Former Integromat)
ioBroker - flexible and modular application for the IoT and Smarthome
Boomi - The #1 Integration Cloud - Build Integrations anytime, anywhere with no coding required using Dell Boomi's industry leading iPaaS platform.
openHAB - "empowering the smart home" - vendor and technology agnostic open source home automation