You might also want to try wxPerl.
wxWindows attempts to create a consistant interface to GUI programming across platforms. Most simplistically it can be thought of as a wrapper for native widget sets. This allows the look and, more importantly, the feel of the application to be native to that platform.
wxPerl is the Perl interface to wxWindows.
Having applications work on win32, *nix, MacOSX (still some problems with wxPerl and OSX last time I tried to compile about 6mo. ago) and feel like native applications is nice.