pyFormex is a tool for generating, manipulating, and transforming large geometrical models of 3D structures by sequences of mathematical transformations. Thanks to a powerful (Python based) scripting language, it is very well suited for the automated design of spatial frame structures. It provides a wide range of operations on surface meshes, like STL type triangulated surfaces. There are provisions to import medical scan images. pyFormex can also be used as a pre- and post-processor for Finite Element analysis programs. Finally, it might be used just for creating some nice graphics.
Goptical is the GNU Optical design and simulation library. It provides model classes for optical components, surfaces, and materials and enables building of optical systems by creating and placing various optical components in a 3D space and simulating light propagation through the system. Classical optical design analysis tools can be used on optical systems. It takes advantages of the C++ object model to allow the building of complex optical systems with a few class instantiations, as optical components are represented by language objects.
Beneath A Binary Sky is an engine that simulates a world in which robots controlled by programs can live, work, fight, and even bear new children. The long-term goal of the project is to create a fully configurable engine that can simulates any kind of world, from simple to complex ones with many rules and events.