All software components of gEDA/gaf are released under the GNU General Public License (GPL) version 2 or later. However, some confusion exists about the schematic symbols. What license do they use? Will GPL symbols “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 gEDA Project is to provide an open-source EDA Suite which may be used for non-commercial 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.
Symbols 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 gEDA Project retains a say in how you redistribute the symbols themselves.
There are three ways a symbol might be distributed:
There is a distinction between cases 1 and (2, 3). In case 1, the object of interest is the symbol library (or individual symbol) itself. In case (2, 3), the object of interest is the design. Some label case 1 “distribution”, and case (2, 3) “use” of the symbol.
Our goals for the symbols are:
The Free Software Foundation has recognized a possible conflict of the base GPL with the use of fonts – and, by analogy, symbols 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:
Therefore, using this as a template, all symbols released with gEDA/gaf are covered under the GPL with the following exception clause:
As a special exception, if you create a design which uses this symbol, and embed this symbol or unaltered portions of this symbol into the design, this symbol 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 symbol, you may extend this exception to your version of the symbol, 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 gEDA Project wishes to use for symbol distribution and use.