Be advised forking from Perl on Win32 is only an emulation, implemented via threads.
in reply to Open doc in Firefox from Tk with no Tk hanging
That said, you might consider Win32::WebBrowser *if* you actually want to open the user's default browser, whether its IE, FF, Opera, or even
Safari. Or you can use its code to figure out how to force FF, its pretty simple, but you need to know the FF executable name/location.
FWIW: Win32::WebBrowser's code is based on something I wrote for a Tk app,
so hopefully it will solve your "hang" issue.
Perl Contrarian & SQL fanboy