All graphics and documentation of Fritzing are licensed under
Creative Commons Attribution-ShareALike 3.0 Unported.
See http://creativecommons.org/licenses/by-sa/3.0/ for the full description.

This means that you may publish circuits and diagrams that you create with 
Fritzing and that use these graphics -- as long as you credit us, and 
publish your works under the same license. 
A credit can be as simple as "this image was created with Fritzing."