By default m3u8 files can be played in Mac Safari browser, but not in any other desktop browsers. What needs to be done to play them in all browsers, both supporting HTML5 and non-HTML5?
Unfortunately HTML5 support for video is so fragmented that it is, to all intents and purposes, useless (at least as a primary focus) at this point in time. M3U8 playlists are Apple HTTP Live Streaming, and as you can tell from the name, they are (or at least started out as) an Apple standard, no other browser uses them, or HTTP Live Streaming.
There are some programs you can install to add support for HLS. Some companies have, for example, produced HLS players written in Flash, or Silverlight. Yospace has produced a flash SDK for HLS playback which includes a JWPlayer mediaprovider which allows you to use JW's automatic HTML5 fallback on non-flash devices (read: iPhone/iPad), while all others get the JWPlayer experience.
There have been many promises from various companies to "standardize browser video support" but they have all (so far) come to nothing, so whatever option you choose, it's going to be a compromise of sorts.