id Tech 5 is the proprietary game engine released by id Software. It follows its predecessors, id Tech 1, 2, 3 and 4, all of which have subsequently been published under the GNU General Public License. It is a major advancement over id Tech 4. The engine was first demonstrated at the WWDC 2007 by John D. Carmack on an eight-core computer; however, the demo used only a single core with single-threaded OpenGL implementation running on a 512 MB 7000 class Quadro video card.