Shuffle along, shuffle along, because this couch is about to get crowded. Alongside the big four, we now have Ubuntu, Firefox OS and the latest version of Tizen all elbowing each other for room. Tizen has one particularly strong backer, Samsung, who built the reference device we play with in the video after the break, and whereas Firefox OS is destined only for the low-end, Tizen seems far more ambitious -- at least judging from the 720p resolution of this developer handset. Since the introduction of version 2.0, the OS is designed to run both native and HTML5 apps, or apps which mix the two layers -- such as the Vimeo app you'll see in the video, which has a web-based interface but accesses the hardware for the purpose of video acceleration.

Huge swathes of the interface are remarkable only by their familiarity: a home screen with a grid of apps; a single navigation button to take you back to this screen or alternatively to a multi-tasking screen by way of a long press; and a top-to-bottom pull-down for notifications and quick access to settings. It's basic, but it represents pretty much what all these new operating systems are supposed to be: ways of getting functionality that is at least close to Android but without all the licensing costs associated with running Google services. Beyond that, however, Tizen at least seems capable of delivering smartphone fundamentals like a fast camera (with burst mode, incidentally). Tizen's mostly likely rival will be Ubuntu, at least once that other Linux-based OS progresses beyond entry-level phones at some point in 2014. From the sound of it though, Tizen is about to beat it to the punch.