%0 Conference Paper %B OSS2005: Open Source Systems %D 2005 %T A Successful Business Model for Free Software %A Ayre, Jamie %A Gasperoni, Franco %X The objective of this article is to offer a return on experience explaining how the legal fundamentals on which Free Software is based allow for a long-lasting business model based on a special kind of expert knowledge-based support that benefits customers and guarantees the creation of a local pool of expertise. This article is based on our experience with GNAT Pro. GNAT Pro is the Free Software development environment for the Ada 95 programming language. It comprises a compiler that is part of GCC (the GNU Compiler Collection), a toolset and graphical Integrated Development Environment, and a set of supporting libraries. Developing, maintaining, and marketing GNAT Pro for ten years have provided significant experience with both technical and non-technical aspects of Free Software. This article summarizes the principal legal and business lessons learned. %B OSS2005: Open Source Systems %P 135-139 %U http://pascal.case.unibz.it/handle/2038/627