TopMod3d is a free, open source, portable, platform independent topological mesh modeling system that allows users to create high genus 2-manifold (watertight) meshes.
TopMod3d can create models that can be developed into flat surfaces using software such as Pepakura, Lamina Design, Rhinoceros3D, and Paracloud. It can also create solid models that can be prototyped using various rapid prototyping technology. Learn more.
Feel free to download the latest version here. If you need help getting started, please visit the Tutorials/Help page and the Discussion Forum. The wiki holds the current version of the user manual and the developer’s manual as well.