Universal Jukebox's name suggests to me that it must play back every type of file I can throw at it. Fortunately, UJ 4 has recently received a major boost in that area and played most of the files I threw at it--including the OGG, Flac and WMA lossless files the previous version wouldn't play. It still doesn't handle AAC, Ape, or Apple lossless so I still have reservations about "universal" in the moniker, but it does play some unusual files, so perhaps it qualifies for "worldly." I found this donationware program generally stable, easy on the eye, easy to use, and well-conceived.
Uncommon files that Universal Jukebox does handle are odd rate/depth wave files such as 24-bit, 88kHz, etc., .wav files. Quite a few players choke on these--not a big deal for most folks, but musicians will run across them now and again.
Universal Jukebox's interface is a four-pane affair with the extra large progress meter/positioning bar and VU meter at the top, a playback control bar below that, playlist and folder panes below the control bar, and the file list at the bottom. There's also a party mode that allows you to more easily control the program DJ-fashion. The whole GUI is easy to get up to speed on--for the most part. The idea of creating a Radio station initially confused me. Then I realized it wasn't Internet Radio, but simply a different type of play list.
All in all, Universal Jukebox is a nice effort with a lot going for it. It may not wean you off of iTunes, but it's definitely worth a look--and it's one to watch for the future.