Google’s Nest Labs is opening its platform to outside developers, a big step by the thermostat and smoke-detector maker to establish itself in a crowded market to be the operating system for Internet-connected devices in the home. Through Nest, users will be able to communicate with appliances from Whirlpool, cars from Daimler AG ‘s Mercedes-Benz, remote controls from Logitech, and other devices. Google itself is a partner, allowing its personal digital assistant, Google Now, to set the temperature on a Nest thermostat automatically when it detects that a user is coming home. Nest will share limited user information with Google and other partners, and people have to opt in for each new device, said Nest co-founder Matt Rogers.