I think largely it depends on whether the app includes any dylibs, frameworks, extensions, etc., of its own (which would also be Universal and thus available for slimming).

And I’m extremely impressed by the ‘nearly a gig’ of space freed-up. I wonder how that translates to a similar trial on an Intel machine…maybe I should find out.

Thanks again for the input

XSlimmer, by default, will not allow you to thin an application that exists in /System, /Library, or /Developer (even though some of these can be slimmed just fine). It also supports a blacklist of applications that cease to work correctly after they’ve been thinned — Linotype FontExplorer X, for example. Also, a preference can be set to backup all applications to another directory before thinning them.

Those three functions make XSlimmer a fair shot safer than using the Tiger-bundled command-line tool lipo to accomplish the same thing. [lipo, for instance, will allow you to overwrite a file, without making a backup first, even if it's a single executable file (or dylib or what-have-you), not just an application bundle (*.app), which is all XSlimmer will allow in my experience of the application.]

I downloaded XSlimmer from MAAD last night, ran it through my entire Applications folder, most of my Developer folder (knowing what not to touch), and ended up saving close to a full gigabyte of space on my PowerBook G4. That’s substantially more than “a couple megs of bloat.”

Those who play things hypercautiously and don’t even like the idea of changing desktop backgrounds or from “Blue” to “Graphite” might want to avoid using XSlimmer, but for most users, XSlimmer takes sufficient safeguards to ensure that any mistakes can be corrected. Just be sure to run the thinned app to make sure it’s A-OK before deleting the backed-up copy.