Excerpt: The licensee is allowed to charge a fee for this service, or do this free of charge. This latter point distinguishes the GPL from software licenses that prohibit commercial redistribution. The FSF argues that free software should not place restrictions on commercial use,[21] and the GPL explicitly states that GPL works may be sold at any price. So to answer the question, “no,” its use does not “infect” other software with the deadly “this has to be free” virus. That being said, there are licenses that do, including the Creative Commons noncommercial licenses. edit for more info Wait! I thought you were asking about commercial use. The GPL does have a copylefting component, as do CC sharealike licenses. That requires sharing source code.