Portal fans are going to love the “Perpetual Testing Initiative” which is a level editor DLC that drops on May 8th for Mac and PC.
Perpetual Testing Initiative (PeTI), which combines a powerful, easy-to-use Puzzle Maker with full Steam Workshop integration, and will be available free for the PC and Mac on May 8th.
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There are already hundreds of incredible Portal 2 puzzles in the wild, but chances are you haven’t played them. They’re hard to find, hard to install, and hard to manage. We’re changing that. Now that we’re adding the Steam Workshop to Portal 2, you’ll be able to browse a virtually endless stream of community-crafted puzzles, then install and play them with just one click from any web browser. Play the most popular maps in the world, or just what your friend created last night.
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With the Puzzle Maker, you can create test chambers of all shapes and sizes. It’s incredibly easy to use — jump right in and start making cool stuff. When you’re happy with your work, publish it to the Workshop for your friends. or even the whole world, to play.
Oh, and let’s be honest, nobody makes an awesome trailer quite like the folks at Valve 
