When I tested the open-source jukebox aTunes, the fast installation was followed by shockingly sluggish tree navigation, required to add my song library. Fortunately, the subsequent scan was flawless, handling 7,500 tracks in about 10 minutes. In music terms, the show started off with some bad feedback, but then aTunes really got rockin'.
There's a lot going on in this iTunes competitor. It's got some failings, notably no plans for firmware-based MP3 player support. That means no iPods or Zunes allowed. aTunes does offer excellent support for players that behave like external hard drives, simply playing songs out of a folder tree similar to the one on your computer. The rest of the program is digital jukebox gold.
The tabbed interface keeps the panes from getting cluttered, managing both primary and secondary information elegantly. Icons just below the Menubar hide the AudioScrobbler, the Navigator, and the Song properties windows, making the UI far more customizable than it might seem. The AudioScrobbler pane surfaces nearly all secondary song information, including an artist's biographical details, using tabs to keep it all organized. Built-in links encourage music and video discovery. There's also 27 skins, built-in support for Last.fm and Internet radio stations, and decent podcast-catching abilities. In short, aTunes doesn't miss a beat and is easily one of the best jukeboxes around.