Three years in, it's safe to say that Apple's (NASDAQ:AAPL) HomeKit platform remains underwhelming. There aren't that many HomeKit-enabled devices, the ones that exist are somewhat expensive, and perhaps most importantly, there a few notable absences. Key among them is Alphabet's (NASDAQ:GOOG) (NASDAQ:GOOGL) Nest, which was the first smart thermostat, a device that was instrumental in jump-starting the smart home market years ago.

Nest has never supported HomeKit, although other smart thermostat makers like ecobee and Honeywell do. But that may be about to change.

HomePod on a white shelf

HomePod will need as much smart home support as it can get. Image source: Apple.

Adding retroactive support

9to5Mac reports that the Alphabet subsidiary is "open to supporting HomeKit" and will "consider HomeKit," thanks to changes in iOS 11 regarding how hardware is authenticated. The changes will make it easier to add HomeKit support to older devices. Apple is shifting toward software authentication, which is necessary if you want to support devices that are already shipping and in circulation.

Apple's MFi accessory licensing program has long required a specific hardware chip. By transitioning to software authentication, third-party accessory makers, including Nest and many others, can more easily add HomeKit support retroactively, potentially opening up Apple's platform to a new wave of existing smart home accessories. The first-generation Nest was released in 2011, three years before HomeKit.

Many have long assumed that Nest's reluctance to support HomeKit was due to the intense rivalry between Apple and Alphabet, but that doesn't line up with the fact that Nest works with Amazon.com's (NASDAQ:AMZN) virtual assistant Alexa (Google once called Amazon its "biggest search competitor"). With Echo, Alexa has already become the pre-eminent virtual assistant for the smart home.

Closing the smart home gap

If the upcoming changes in iOS 11 can successfully expand the number of supported HomeKit devices, that will give Apple's forthcoming HomePod much better positioning. As it stands, HomePod is lacking compared to the Echo in the smart home, and the company is betting (again) that high-fidelity audio can justify the hefty $350 price tag. For what it's worth, CEO Tim Cook expressed confidence in a Bloomberg Businessweek interview published this week that HomePod will offer compelling value at that price point. "It's gonna rock the house," Cook said.

Nest has had its own fair share of turmoil, missing revenue projections over the years; founder Tony Fadell stepped down as CEO last year. Adding HomeKit support for its flagship product could help the Alphabet subsidiary boost its own sales, broadening its addressable market to iOS users -- and there are a lot of them. After that, hopefully Nest will consider adding HomeKit support to its other products, such as its Protect smoke/carbon monoxide detector.

Seeing as how smart home capabilities and music streaming are the two most important areas where HomePod and Echo will compete, if Apple can catch up in the smart home by any means necessary, HomePod will have a much better chance of succeeding and avoiding the fate of the iPod Hi-Fi.

Suzanne Frey, an executive at Alphabet, is a member of The Motley Fool's board of directors. Evan Niu, CFA, owns shares of Apple. The Motley Fool owns shares of and recommends Alphabet (A and C shares), Amazon, and Apple. The Motley Fool has a disclosure policy.