Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
Bosch IoT Suite - Bosch IoT Suite provides solutions to realize innovative business models in the Internet of Things and cross-domain applications.
ioBroker - flexible and modular application for the IoT and Smarthome
Azure IoT Hub - Manage billions of IoT devices with Azure IoT Hub, a cloud platform that lets you easily connect, monitor, provision, and configure IoT devices.
openHAB - "empowering the smart home" - vendor and technology agnostic open source home automation
Hologram.io - Cellular IoT connectivity that powers innovation