You have a point here. Before using open souce software you should read its license and decide if it is appropriate for you.
On the other hand majority of CPAN modules (but not all!) are dual licensed under GPL/Artistic. And Artistic is very
flexible license with nearly no restrictions. I doubt using Artistic licensed modules can get you in any trouble.
Ilya Martynov, email@example.com
CTO IPonWEB (UK) Ltd
Quality Perl Programming and Unix Support
UK managed @ offshore prices - http://www.iponweb.net
Personal website - http://martynov.org