lowell wrote: An obviously newbish question: I've got mplayer working standalone; now how do I name it as the app to play files with in Mozilla? I looked around in preferences but nothing was too apparent (it needs to be REALLY apparent for me...:-( .) TIA You need a seperate plugin called mplayer-plugin that allows mplayer to run within a browser. If you want to simply automatically execute mplayer to handle a particular file type, "Helper Applications" can accomplish that.