How Is CUPS Licensed?

CUPS is provided under the GNU General Public License ("GPL") and GNU Library General Public License ("LGPL"), Version 2. A copy of these licenses can be found here.

The GNU LGPL applies to the CUPS 1.1 API library, located in the "cups" subdirectory of the CUPS 1.1 source distribution and in the "/usr/include/cups" directory and "/usr/lib/libcups.so" or "/usr/lib32/libcups.so" files in the binary distributions.

The GNU GPL applies to the remainder of the CUPS distribution, including the "pstoraster" filter which is based upon GNU Ghostscript 5.50.

For those not familiar with the GNU GPL, the license basically allows you to:

• Use the CUPS software at no charge.
• Distribute verbatim copies of the software in source or binary form.
• Sell verbatim copies of the software for a media fee, or sell support for the software.
• Distribute or sell printer drivers and filters that use the CUPS API so long as source code is made available under the GPL.

What this license does not allow you to do is make changes or add features to CUPS and then sell a binary distribution without source code. You must provide source for any new drivers, changes, or additions to the software, and all code must be provided under the GPL.

The GNU LGPL relaxes the "link-to" restriction, allowing you to develop applications that use the CUPS API library under other licenses and/or conditions as appropriate for your application.