My iMac and iPad play anything on Youtube and other video presentations
on the web just fine. So does my wife's iPhone.
If you right click on any of them I think you will find that they are
presented in "Adobe Flash Player". I've uploaded over 150 videos to
YouTube, some in .wmv, some in .avi and some in .mp4. When you play
them they are all presented in Flash Player.
I call misnomer. Anyone who's uploaded over 150 videos to YouTube isn't qualified to be called Mr.
Luddite.
:-) Most of them are music videos of the Bob Dylan wannabies who
sing and howl at the Open Mics we've had over the years.