As soon as I get (the official) OS2008 I definitely intend to pack up my old OS2007 runtime libraries and install them somewhere in OS2008. As benmhall said, that's supposed to work. I'm just hoping that there's no such silliness as forgetting to update the shared library major number in those upgraded OS2008 versions (that would be terribly incompetent if so). And even if they didn't, I'll put the libs somewhere out of /lib /usr/lib and try my old applications with a runtime wrapper.