Carmack introduced the technology, saying, "So the last couple of years at id we've been working in secrecy on next-gen tech and a game for it ... this is the first time we're showing anything we've done on it publicly." He describes the demo happening on screen: "What we've got here is the entire world with unique textures, 20GB of textures covering this track. They can go in and look at the world and, say, change the color of the mountaintop, or carve their name into the rock. They can change as much as they want on surfaces with no impact on the game."
Carmack finished off the tease saying, "We're going to be showing on a Mac, PC, PS3, and Xbox at E3, we'll have another Mac announcement at E3." Wow, talk about multiplatform. Check out some pics of the id Tech 5 demo from Engadget after the break.