While iTunes is free, it is a propriety project which keeps you from making changes to it. If you are looking for an open source version of iTunes, check out aTunes (http://www.atunes.org/). It does all the good stuff that iTunes does: it plays mp3, flac, wma, ogg, wav, mp4 files; it has streaming radio; you can associate metadata and tags with songs; organize your music and rip audio CDs. And since it's open sourced, you can contribute to the project and make the changes you want.