&gt;&gt;&gt; GPL works well to protect the freedom of its users.<p>&gt;&gt; As do the BSD and especially(?) the Apache Software License.<p>&gt; Nope. As a user of a closed source program built on top of BSD or ASL license...<p>Bam. Got you. You, and the Mac users mentioned in the other comment weren&#x27;t using open source software.<p>Users of the original software are still protected.<p>&gt; I certainly don&#x27;t have the rights I would have had if the bottom layers were GPL.<p>You wouldn&#x27;t anyway. They&#x27;d just use something else.