Netflix explains in this post how they use HTML5 for their UI frontend and logic
HTML5 brings to the table, the freedom to create rich, dynamic and interactive experiences for any platform with a web browser. In fact, we’re also using HTML5 to create the user experience for our iPhone, iPad and Android applications as well
[…] HTML5 […] is delivered from Netflix servers every time you launch our application. This means we can constantly update, test and improve the experience we offer. […] Our customers don’t have to go through a manual process to install new software every time we make a change, it “just happens.”
[…] our world class UI engineers can seamlessly move between working on our website, our mobile experience, and our television-based applications.
This clip shows a sample of how that HTML5-based UI looks on a PS3.