Mars MOLA Viewer displays a fly-over rendering of the Martian surface, as measured by the Mars Global Surveyor, in real-time 3D animation. It downloads the Mars Orbiting Laser Altimeter topographic data files and uses them to drive the rendering. The user controls the position and the angle of the camera, and can move seamlessly over the entire Martian surface from -88 to 88 degrees latitude. It is a Java Web Start program with 1-click installation from your browser (depending on platform/browser).
Aviascene is a virtual environment for remote exploration. Users can download actual earth topography and surface data from USGS, then go exploring. If they get lost, they can launch an aircraft to reconnoiter. It features a high- performance adaptive OpenGL terrain renderer, airplane and wheeled vehicle physics models, and the ability to mark waypoints at GPS coordinates. It can be used to plan a backpacking trip or just as a flight simulator.
Micropolis is a city simulation game engine based on the original classic SimCity source code. Micropolis is based on the Tcl/Tk version of SimCity. It consists of the micropolis module, which is the engine recast as a C++ class; the cellengine module, which is a cellular automata machine engine; and the tileengine module, which is a Cairo based tile renderer. It is intended to be used with the OLPC's Sugar user interface environment, but layered so the core code is useful in other contexts.