Manifold is a program I’ve written for creating papercraft models of polyhedra, like these:

I got started in papercraft by buying an automated paper cutting machine (a Silhouette Cameo). This is essentially a CNC router, except that it has a blade for cutting paper instead of a spinning router bit. It makes cutting out the models trivial—gluing them together is the hard part.

Models in the papercraft community are often created by using 3D software and then “unfolding” the 3D models into one or more flat segments that can be folded and glued into the 3D shape. Manifold takes a different approach: you design the flat portions directly. For example, you can build the following flat model that can be folded into a dodecahedron:

This takes some imagination but it’s a lot of fun. Check out Manifold here.