Evolvotron is an interactive "generative art" application to evolve images/textures/patterns through an iterative process of random mutation and user-selection driven evolution. If you like lava lamps, and never got tired of the Mandelbrot set, this could be the software for you. It's implemented using Qt, and is multithreaded.
peekabot is a versatile 3D visualization tool targeted at robotics researchers and developers. It's multi-platform, general purpose, easily extendable, scalable, and does not depend on any other frameworks to function. It also provides some functionality for interacting with your robots using the GUI. You can test your algorithms in both simulated and real environments. The only requirement is that the device can use TCP/IP.
GPlates offers a novel combination of interactive plate-tectonic reconstructions, geographic information system (GIS) functionality, and raster data visualization. GPlates enables both the visualization and the manipulation of plate-tectonic reconstructions and associated geological, geophysical, and paleo-geographic data through geological time.