Well, in Windows at least, the Windows terminology is 'Close'. If you click the top left icon for any window it will present the standard window menu including Close. Therefore I don't think many people will be so confused if programmers switch to 'Close' instead of 'Exit' - it may confuse for the first couple of times, but at any rate I always close programs with the big red X and never off a menu anyway. In fact I dislike menus and use toolbars wherever possible; pictures and positions are far more memorable than text (especially text that changes position - I always make the full menus appear.. I should probably turn off the menu contraction thing).