will require Silverlight 5 a small, lightweight and FREE browser plug-in from Microsoft.
to install Silverlight on Windows and Mac
It’s a small FREE browser plug-in from Microsoft that's very similar to the Flash Player
which is used by the BBC iPlayer for example.
Yes, absolutely! It’s a bona fide official Microsoft product. It is offered free
Windows Live Essentials
There is a good description of Silverlight on Wikipedia
. You can also visit the Official Silverlight site