What is this "Install Media Player" Window That Popped Up?

Am I the only one getting this?

When I went to the GWM main site, and clicked on "home," big page opened up insisting that I download an update to my "Media Player".

So far as I know, I don't have anything called "Media Player" on my computer (I've got Adobe and Microsoft players, but not this).

Is this legit, or a virus that's crept into the GWM site?

Questionable website address (at top of the page): http//  (added spaces to avoid hotlink) mediaplayer.browserupdater.org/2/index.php?s=2491945128