The Foundation for Economic Education publishes a journal called 'The Freeman: Ideas on Liberty'. They published this article in January:
Open-Source Software: Who Needs Intellectual Property?
by Michele Boldrin and David K. Levine
The market for open-source software—uncopyrighted, freely reproducible computer programs—is not well understood by economists. A central source of surprise is that innovation can thrive in a market without traditional intellectual property (IP). But as we argued in a 2005 unpublished paper, "Perfectly Competitive Innovation," as a matter of theory there is no reason to believe that monopoly power through IP is needed for innovation. The market for open-source software is the poster child for this perspective.