A step forward in increasing the compatibility between smart home IoT products is going on through the Zigbee Alliance. They just announced the Project Connected Home over IP in partnership with Amazon, Google, and Apple. The top players in the home IoT consumer products along with the members of the Zigbee Alliance that also includes Samsung, IKEA, Phillips, and other manufacturers are working towards a more streamlined manufacturing process and more inter-compatibility between the consumer products, such as Alexa, Google Assistant, and Siri. Moreover, the working group material is being open sourced on GitHub. This initiative is timely when the industry is witnessing a huge growth in demand and data stream of the billions and billions of small devices connecting together via the Internet. Their work is also open sourced on a GitHub repo - project-chip/connectedhomeip.
(photo taken from zigbee alliance announcement)