And make maps shaped like penises, probably. The Perpetual Testing Initiative offers players a map-editing tool, which looks a lot like this, so fans can make testing chambers to rival GLaDOS'.
Portal 2 has sold more than 4 million units worldwide since its launch on April 18, 2011, and Valve is slowly but steadily (mostly slowly) supporting it with new content, such as today's batch of DLC, the Perpetual Testing Initiative.
