When you access this program from your browser, is it running on the same machine as when you checked it from a command line? If not, are you sure all the modules you need are installed on the web server? The fact that carp isn't returning any useful info makes me wonder if your program died in a use statement before the use CGI::Carp (or in the use CGI::Carp itself!). Also, make sure your shebang line (#!/usr/bin/perl, e.g.) is correct for the system you're running on. Last, as noted above, check your HTTP header. Probably the most common mistake is forgetting to put two endlines after after it, before the HTML.