This is a C implementation of the powercrust algorithm, using the hull convex hull code by Ken Clarkson. It is released under the GNU Public License. It is built to run on Linux, although it has been ported to Windows by Patrick Min and also to work with VTK by Tim Hutton.

Code:
powercrust.tar.gz

References:
Amenta, Choi and Kolluri, The power crust, 6th ACM Symposium on Solid Modeling, 2001, pages 249-260
Amenta, Choi and Kolluri, The power crust, unions of balls, and the medial axis transform, Computational Geometry: Theory and Applications, 2001, 19:(2-3), pages 127-153.