Page:Shrinking the Commons.djvu/14

 The so called “copyleft” condition, a provision included in one form or another since GPLv1, limits the ability of authors of works derived from GPL-licensed software to release their own work under licenses more restrictive than the GPL. In its current form, the provision requires authors of a modified version of software derived from GPL-licensed code to “license the entire work, as a whole, under this License to anyone who comes into possession of a copy. This License will therefore apply. . . to the whole of the work, and all its parts, regardless of how they are packaged.”

In a license document that otherwise celebrates freedom and choice, the copyleft condition at first seems out of place. It limits, rather than enhances, one potentially important freedom enjoyed by users of the software—the freedom to license derivative software works they create on terms of their choosing. It is surely this loss of freedom that underlies pejorative labels, such as “viral” or “infectious,” that critics sometimes use in describing the GPL or other copyleft licenses. As a programmer, using GPL-licensed code in your own work makes you a FOSS author whether you wish to be or not, because the copyleft condition “infects” your final