HTML5 Extension for Windows Media Player Firefox Plug-in - Interoperability Bridges and Labs CenterHTML5 Extension for Windows Media Player Firefox Plug-in The HTML5 Extension for Windows Media Player Firefox Plug-in is an add-on that enables Firefox users to play H.264-encoded videos on HTML5 pages by using the built-in capabilities found in Windows 7. This Extension adds to the functionality of the extremely popular earlier Windows Media Player Plug-in for Firefox to enable web pages that use
