M3U8 - UTF-8 M3U Playlist File is a file extension that supports many different applications, and you will be able to take advantage of it. Windows Media Player, Winamp, and iTunes are just a few of the players that are supported by this file extension. When you think of a M3U file, you may think of a plain text file, and that is exactly what it is. This file extension is great because it will give you the location specifically of just one or various different media files. There are also comments that may be included within the M3U file that you can take advantage of as well. You can gain access to this amazing file extension by simply going online, and using your sources.