Kludge3d is a simple 3D model editor in the spirit of Worldcraft or Milkshape.
It is the offspring of several other GTK-based editors, with the best features
taken from each. As the name implies, kludge3d is a kludge.
CityBuilder is an attempt to automate much of the work involved in creating large virtual urban landscapes. The system takes a street map as input and produces street geometry and a scene graph as output. Applications include games (think GTA*), etc.