I have HLS m3u8 that plays well on IOS and Android with html5 <video>
But does not play on desktop PC or desktop MAC (Chrome, Firefox)
How to play m3u8 on desktop PCs ?
Is there a streaming format of video that would play both on desktop and mobile ?
HLS will only work on desktop in Mac OS Safari 6+. Have a look here for reference.
For HTML5 video on desktop you can think about using MPEG DASH. It has a JS lib that works both live and on demand with the following browsers:
As of 8/30/13, Desktop Chrome, Desktop Internet Explorer 11, and Mobile Chrome Beta for Android are the only browsers supported.
If you want wider browser/device coverage with adaptive streaming technology you will need to consider using Flash which supports RTMP and HDS or Silverlight with Smooth Streaming (Flash has better coverage I should say).
Most media companies today uses an hybrid approach Flash (HDS/RTMP - desktop) / HTML5 (HLS - mobile) checking with JavaScript beforehand on the device what can be read and delivering the appropriate player/streaming protocol as a result.
FYI you can play HLS stream with software like VLC on Windows desktop.