Being able to use the same Perl program (pretty much) on whatever platform I want (provided the modules I need are all there). That way I can write one or two basic templates for my team to use and it won't matter if they have to use it on a Windows server or on a Unix server because I can put the platform dependent functions into a module and its handled in the background, the same information is passed to the function regardless of platform. I also use it to write reports and dig for information.