2D Apollonius Graphs
An Apollonius graph is also known as an additively weighted Voronoï diagram. Roughly speaking, this is the Voronoï diagram of a series of weighted points, that can be seen as circles (whose radii are the weights). When all the weights are equal, this is the ordinary Voronoï diagram.
Some documentation can be found on the CGAL website and in this folder.
This package is provided under the GPL-3 license but it uses the C++ library CGAL which requires a license from the GeometryFactory if you wish to use it for commercial purposes.