All software components of pcb-fpw are released under the
GNU General Public License (GPL) version 2 or later.
However, some confusion exists about the footprints.
What license do they use? Will GPL footprints "infect" your design, thereby
requiring you to release your design to the public ?
If you modify the symbols, must you release the modified versions under the
GPL ?
The goal of the pcb-fpw Project is to provide an open-source EDA Suite which may
be used for non-commerical as well as commercial projects.
Our tools are aimed for use by students, hobbyists, educators, consultants,
and -- yes -- corporate engineers.
We are not interested in exerting any control over your designs, or forcing you
to reveal proprietary information contained in your designs.
Footprints are similar to the font files used in document processing software
-- they are graphical objects used to express your ideas.
We want you to retain control of your own ideas (your design), while the
pcb-fpw Project retains a say in how you redistribute the footprints themselves.
There are three ways a footprint might be distributed:
Our goals for the footprints are:
The Free Software Foundation has recognized a possible conflict of
the base GPL with the use of fonts -- and, by analogy, footprints used in
case (2, 3).
Their solution is to use an exemption clause in the GPL which you explicitly
insert for fonts.
Read about it here:
http://www.fsf.org/licensing/licenses/gpl-faq.html#FontExceptionTherefore, using this as a template, all footprints released with pcb-fpw are covered under the GPL with the following exception clause:
As a special exception, if you create a design which uses this footprint, and embed this footprint or unaltered portions of this footprint into the design, this footprint does not by itself cause the resulting design to be covered by the GNU General Public License.
This exception does not however invalidate any other reasons why the design itself might be covered by the GNU General Public License.
If you modify this footprint, you may extend this exception to your version of the footprint, but you are not obligated to do so.
If you do not wish to do so, delete this exception statement from your version.
The idea is that case 1 redistribution is covered under the GPL, but
distribution of your design (case (2, 3)) is exempt from the GPL.
This is the scheme which the pcb-fpw Project wishes to use for footprint
distribution and use.