It's true that one language will have advantages over another in terms of particular features, but these mostly relate to the effectiveness and sanity of programmers, rather than the range of functionality (the "apps") that can be accomplished. Also, the features that are "better" in one language are usually offset by others that are better in the other -- e.g. greater run-time efficiency vs. faster development/prototyping.
But I'd have to say that the first two replies on this thread are totally correct. Perl is an application that is platform independent, and provides users with a degree of power and flexibility that is hard to beat. And CPAN -- especially CPAN.pm -- is something quite unique: an intelligent, easy-to-use tool that really delivers the promise of re-usable code (a stark contrast to, e.g., the "dll hell" of MS-based C++ apps; I always wonder how many functions, in how many different dll files, were written independently to do the same thing... or try to do the same thing, but fail in their various independent ways.)