I had my share of endeavours with closed and open home automation solutions and this one really hit it off.
openHAB is an amazingly flexible center for your smart home, regardless if you are playing around with ESP8266's or driving a whole KNX installation. It's open source and the ~120 Add-ons can talk to nearly everything out there, from Z-Wave over Alexa and IFTTT up to whatever you get onto MQTT.
Check it out.