Rather than copying Chromecast to webOS, LG released an open source Connect SDK late last week that integrates media casting, making it easier for developers to bring their apps to connected devices such as Roku streaming boxes, Google’s Chromecast, Amazon’s Fire TV and LG’s own TV sets. By combining existing multiscreen and home sharing protocols such as Google’s Cast SDK, DLNA and DIAL, developers’ mobile apps only need one set of code to work on a variety of big screen devices.

Developers can use one unified API through Connect SDK to launch existing apps or prompt users to download an app through a connected TV app store. LG also hopes to add support for Apple TV and Samsung devices.

“So why would LG build technology that makes it easier for developers to interact with Roku boxes or Amazon’s Fire TV?” asks GigaOM.

“The answer is simple: Because that’s what’s in our living rooms. ‘People don’t just use devices from one company,’ Colin Zaho, LG director of product management, said. That’s why developers shouldn’t target just one device, or think in the framework of ecosystems that they need to target. ‘For the user, the ecosystem is what they have in their room,’ added Ohad Ben-Yoseph, LG’s director of business development.”

LG will ultimately benefit because developers will automatically be able to make apps for LG’s webOS TVs alongside other more established platforms, such as Chromecast and Roku.

Though LG is competing with Apple’s Airplay and Samsung’s own version of multiscreen SDK, Zaho believes it is still important to encourage collaboration between app developers and integration between devices. “We want to drive the whole industry forward,” he said.

The GigaOM post includes a video demo. The SDK can be downloaded here.