The Portal Mappers Group

"Portal". A Valve game with developers from the game "Narbacular Drop" have come together to make a game now called "Portal". In portal, you are a test subject in the Aperture Science Laboratories. In the game, you find a gun called the "Handheld Portal Device", that can make two interlinked portals that you must use to solve brain-busting challenges.
For the people that have already beaten "Portal", the game is very short. Now, you can now expand the game by joining the group, and make your own maps!
Mapper or not, everyone's welcome!