LG and TP Vision (the new owner of Philips’s TV business) are officially establishing the Smart TV Alliance, providing a common software ecosystem that allows developers to write apps once for multiple smart TV platforms. The sparse members list (just LG and TP Vision) can be expected to grow as the press release notes "other Japanese manufacturers" are in the process of joining. When the project was first announced at IFA in Berlin, Sharp was listed as a partner, and its current omission is likely just a formality.
It's no secret that the smart TV market is severely fragmented, with everything from Samsung's Smart TV to Google TV vying for developer attention, and the Alliance is hoping to focus some of that energy on a single, common goal. The SDK is based on web standards like HTML5, and you can download it now from the Alliance’s site. A newer 2.0 version with additional (but as yet unannounced) specifications is in the works as well, and should be coming at the end of the year.