Owned by Generac now, I believe.
Not that it has anything to do with it.
My memory says that this model dates back to 2007-2008.
The original Smart thermostat and the original EMS thermostat are also not compatible with the same portal as thermostats they have made since 2012.
One of my friends has a Smart Si that I purchased in 2012, and it is still supported (along with the EMS Si).
Probably does. This 17 year old thermostat (and the EMS equivalent) use a different portal than products made since 2012. It probably isn't cost-effective to support the old portal anymore.
I wonder how far back Z-wave thermostats go?
They'd be considered 'smart', no?
While ecobee never made any, z-wave thermostats have probably existed for close to 20 years.
So, could they be considered the original 'smart' thermostats?
Probably not. There were X10 thermostat set back controllers that worked with generic thermostats to fool them into to turn heating/cooling on. And Lutron's Radio RA dates back to 1997. There are thermostats for Radio RA, but I don't know when they were released.
Actually, the earliest known smart thermostat controller was my father. I know that for a fact because when I was a kid he would yell at me "Do not turn down the AC setting! It's cold enough!!" 
