Via UFO-au:

Topostruct is a program for structural topology optimization written by Sawako Kaijima and Michalatos Panagiotis.  It’s development was influenced by the ideas and methods discussed in the book “Topology Optimization, Theory, Methods and Applications” written by M.P. Bendsoe and O. Sigmund.

The software is intended primarily towards designers and non engineers that want to familiarize with topology optimization as well as develop their intuition regarding the structural behaviour of materials.
Topostruct supports both two and three dimensional models.   The user will input the dimensions and resolution of an orthogonal region in space which will be assigned certain material density.  The user must then place different support conditions and applied loads within this region and finally run the optimizer which will yield a distribution of material that best meets these conditions.

Topostruct is available from kaijima & panagiotis’s website http://sawapan.eu/ which has a number of other generative design applets for download.