Hello, I am working on an open source 3D solid modeling kernel ( http://wildcat-cad.blogger.com and http://wildcat-cad.googlecode.com). It allows users to sketch 2D profiles and extrude them into 3D to form mechanical parts. The 2D sketches are constrained with dimensions (lengths, angles, etc.) and these constraints naturally form a system of equations. An unrelated project (http://code.google.com/p/psketcher) has developed a very nice solver for these systems of equations. The psketcher project uses GiNaC as its mathematical engine. I would like to incorporate the psketcher solver into my kernel, but there may be a conflict in licenses. My project is released under the BSD license, while I understand GiNaC to be under the GPL. Is there any way to reconcile this problem other than changing to a different license? I would love to use GiNaC for a couple of other purposes within my project also. Any help would be appreciated. Cheers, Graham