This is a quick overview between Silverlight, Flash and HTML5
Working in fullscreen on one display while still being able to use the other out of the box, Which is great for guys with dual monitors.
Less processor intensive on high-res video, Its really smooth.
And what I really like too much about it, Is that it WILL continue to buffer video even if a connection is lost and reconnected.
It is made by Microsoft but it also works on OS X [On OSX it works better than flash]
Great for almost everything, Except videos.
Easy to work with.
No additional programs or plugins are required.
It does the trick for videos.