RM files are video files, as far as I know. I mentionned Exaile and such as alternatives to Amarok (which is designed for KDE (including Kubuntu) and not for XFCE (including Xubuntu)). To read video files, you indeed need a video player. TOtem, VLC and MPlayer are the most famous ones, but if there is a file VLC can't play, then the two others won't either. And RM files can only be read with RealPlayer. You can get RealPlayer 10 from the medibuntu repository (<a href="http://www.medibuntu.org/">http://www.medibuntu.org/</a>) or RealPlayer 11 for Linux here : <a href="http://europe.real.com/realplayer/other-versions/">http://europe.real.com/realplayer/other-versions/</a> . Note that in both cases, we will not be able to provide you support for it, as it is an external repository that is not checked by the community, for applications that are not Free.