Is there a way to use NetBeans or Eclipse for an old Perl CGI application in a Windows environment?
I currently have NetBeans for PHP.
NOTE: I am a .NET dev and have done PHP back in the day. I know very little about CGI, I just need to modify an existing legacy app.
If you got only one CGI application: Use a text editor or use the IDEs you know as text editors to edit this file.
Eclipse has a EPIC plugin which could handle Perl files up to some point.
If you want to edit more than one Perl application, try out Padre, the Perl IDE. It's written in Perl and mostly for Perl (but it supports many other languages like PHP and some non-languages like CSS or HTML).
You could get it from CPAN using your installed CPAN client or from the Padre download page at http://padre.perlide.org/download.html if you don't have any installed Perl.
The download package includes Strawberry Perl which is a full Perl interpreter for windows.