David Colleen (Cornell Bachelor of Architecture, 1981) is an architect who began his practice in 1981 working on the design of large buildings. In 1995, he founded Planet 9 Studios, which produced the Internet's first commercial 3D applications and virtual places. Today, Planet 9 is a leading supplier of 3D urban simulation applications (RayGun and GeoFeeder) and research. Planet 9 has also produced more than 50 virtual cities which are used by architects, engineers, researchers, film producers, game developers and others interested in using realistic city backdrops in animations and real-time applications. Customers include Activision, AOL, Clarion, the Discovery Channel, NASA, Microsoft, Sprint and the U.S. Army.