Netflix uses Microsoft's Silverlight plug-in to deliver its streaming video. It works fairly well on OS X and Windows, but it's not a viable option on Linux, mobile devices, or set-top boxes. At this point, the writing is on the wall in regard to the future of Flash and Silverlight. A different playback method is necessary going forward, and HTML5 video is the obvious choice here. Sadly, there are numerous obstacles in the way -- DRM being the biggest.