With smart speaker Echo and its voice assistant Alexa, Amazon turned its attention to voice-controlled devices, forging partnerships with startups and other companies. With Echo, users can control thermostats from Ecobee, talk to Invoxia SAS’s portable speaker and, soon, open the garage or start the engine of a Ford automobile. As more developers integrate Echo into their products, Amazon is better able to compete against Apple’s Siri, Microsoft’s Cortana, and similar technology that Google is presently working on.

The Wall Street Journal notes that, although “Alexa is still a work in progress,” the $180 Echo “can pick up voices from across a room and respond to queries like traffic reports or trivia in less than two seconds.”

“Voice is just so natural,” said First Round Capital partner Howard Morgan, whose company has also invested in Uber and food-delivery startup Blue Apron. “It’s much quicker than typing. We’re encouraging our portfolio companies to consider using Alexa. Simply, it removes one barrier to getting people to use your service.”

Echo, which began as Amazon chief executive Jeff Bezos’ inspiration from the spaceship computer on “Star Trek,” was in development for four years, and uses technology created in-house enhanced by outside technologies such as that from text-to-speech system IVONA.

Amazon executive David Limp says that the company was “surprised by the immediate demand from software developers,” and as the company added more services, including Pandora and Domino’s Pizza, the device “gained steam.” According to Consumer Intelligence Research Partners, Amazon has likely sold about three million units.

Amazon recently debuted less expensive versions of Echo, including the $90 Echo Dot, and its Lab126 hardware unit is working on “an Alexa-powered device featuring a tablet-like computer screen,” dubbed internally as “Knight.”

“We believe the next inflection point in terms of user interface is voice,” said Limp. Among the companies using or planning to use Echo for voice-activated functionality are Scout home-monitoring devices, Bot Home, Wi-Fi router company Luma Home and Web-connected doll maker Toymail.

Echo isn’t the only technology that Amazon is pushing into the hands of third-party developers. Wired reports that Amazon has listed a customizable version of its Amazon Dash Button, which, with one-click lets the user order products by pressing an Internet-connected physical button. The customizable AWS IoT Buttons are for sale for $19.95 on its site, pitched as “a way for developers to learn how to use the company’s various cloud services, including its ‘IoT’ offering for powering Internet of Things devices.”