YouTube Feather is a new feature of YouTube which let the videos load faster on your web browser. This is an opt-in beta for "Feather" support on YouTube. The "Feather" project is intended to serve YouTube video watch pages with the lowest latency possible.
YouTube Feather achieves this by severely limiting the features available to the viewer and making use of advanced web techniques for reducing the total amount of bytes downloaded by the browser. It is a work in progress and may not work for all videos
Go to YouTube.com/feather_beta Join YouTube Feather