m3u playlists are used often on the Net to stream music.
M3U2iTunes is a helper application which overcomes the problems iTunes has with m3u playlists.
iTunes, when downloading an m3u playlist, places all songs scattered throughout the main library (rather than, say, creating a playlist and organizing the stream tracks in it).
M3U2iTunes simply creates a single playlist named "M3U Internet Stream" and places all songs from the downloaded m3u playlist into the M3U Internet Stream playlist.
M3U Internet Stream is always used as the target for m3u playlists. Rather than creating a new playlist each time, the M3U Internet Stream playlist is removed and recreated (so you won't have a huge mess of new playlists in your iTunes libraries).
M3U2iTunes is freeware, and is unsupported.
The Macintosh version of M3U2iTunes is an AppleScript application, built using XCode. To install it:
To uninstall M3U2iTunes, simply drag it to the Trash. You'll want to (probably) redo the association between .m3u files and iTunes in this case, so find a .m3u file (probably in the Trash since that's where M3U2iTunes will have been putting them), select it and then choose File->Get Info in the Finder. Change Open with back to iTunes and press the "Change All" button.
The Windows version of M3U2iTunes is a C++ application which makes use of the iTunes COM for Windows SDK to drive iTunes. To install it:
After the install is complete, all m3u files should be associated with M3U2iTunes. If you double click on an m3u file (or download one over the Net), it will cause M3U2iTunes to be launched, which will in turn start iTunes, put all of the songs into the M3U Internet Stream playlist and start it playing.
To uninstall M3U2iTunes, simply use Add/Remove Programs in Control Panel.