The GPL font exception clause is an optional clause that can be added to the GNU General Public License permitting digital fonts shared with that license to be embedded within a digital documentfile without requiring the document itself to also be shared with GPL. Without the clause, conflicts may arise with open-source projects distributing digital fonts which may be used in desktop publishing. As explained by Dave Crossland in Libre Graphics Magazine, "A copyleft font may overreach into the documents that use it, unless an exception is made to the normal terms; an additional permission to allow people to combine parts of a font with a document without affecting the license of texts, photographs, illustrations and designs. Most libre fonts today have such a copyleft license – the SIL OFL or GNU GPL with the Font Exception described in the GPL FAQ."
Origin
The font exception was authored in April 2005 by David "Novalis" Turner, a Free Software Foundation GPL compliance engineer. As he explains, "The situation we were considering was one where a font was embedded in a document. Embedding allows a document to be viewed as the author intended it even on machines that don't have that font installed. So, the document would be derived from the font program. The text of the document, of course, would be unrestricted when distributed without the font." To be in compliance with the GPL, Red Hat's Fedora Linux project included the font exception with the license for its Liberation font package, albeit with additional restrictions in 2007. These restrictions prompted further discussion among the Debian GNU/Linux distribution's community members concerning the GPL+FE. This attention prompted Ubuntu to follow suit and create the Ubuntu Font License because they were not satisfied with either the SIL OFL or with GPL+FE.
Usage
To indicate a font exception to the GPL, a digital fontcreator adds the following language to the end of the GPL text distributed with their font:
