It looks like a beta version of the Portal 2 Authoring Tools (Hammer map editor, etc.) are now live on Steam!

To install them, go to your Library and select Tools, and from there you can simply install and start using them!

Release news at the official Portal 2 site

Hey all, neighborhood moderator WinstonSmith here. We're starting a bit of a "Community Roundup" thing at TWP considering that people have begun to do wonderful things with the Alien Swarm SDK (interested? Check around for more info!). Most are singleplayer maps, but we have a multiplayer map in there too and a few neat tools people have thrown together. So, without further ado:

Singleplayer:
Synchronicity
Created by Omnicoder, Synchronicity is a well-rounded demonstration of many of Portal 2's concepts, including the Discouragement Beam, Light Bridge, different gels, and Excursion Funnel. As usual, Omni is able to create intriguing puzzles in small spaces without becoming frustrating.

Sequential--Part 1
Created by Nightgunner5, the first part of Sequential is well-done. It contains puzzles utilizing many Portal 2 mechanics and has rather pretty lighting to boot. It concludes (for now) with a rather tough beam redirection puzzle.

Gravity Trials
Created by naitoookami, Gravity Trials explores the concept of (as you may have guessed) switching gravity. While not the most complex puzzles, it sets the stage for future use of gravity-oriented puzzles.

Multiplayer:
Colours Co-Op Part 1
Created by IanB, this short but satisfying map has a slightly different style than Portal 2. All the same, it looks fantastic and the creative voicework makes it a must-play.

Tools:
Crook's Custom Maps to Extras App--Parses custom maps found in the Portal 2 maps folder and adds them to the extras.txt file, letting you launch them from the Extras Menu.
Nightgunner5's Extras Patcher--Assists in adding maps to the Extras menu.
Haavapuo's Extras Menu Patcher--Another tool to add maps to the Extras menu.
Magic94's Map Loader/Starter--Another tool that copys maps to Portal 2's folder and launches it.
Omnicoder's Custom FGD--Use this to map for Portal 2. Updated version is in the description.

Enjoy!

(Note: as of right now I'm only taking released maps, not WIPs. Partly because I'm a bit pressed for time at the moment, I'll probably look at them later.)

No word on the SDK, but Portal 2 DLC will be coming soon with a price tag of $0.00!

Quote:
"Valve, creators of best-selling game franchises (such as Half-Life, Left 4 Dead, Team Fortress, and Counter-Strike) and leading technologies (such as Steam and Source), today announced the first game add-on for the year's highest rated multiplatform game, Portal 2, is in development and targeted for this summer.

Portal 2 DLC #1 will offer new test chambers for players, leaderboards, challenge mode for single and multiplayer modes, and more.

Targeted for release this summer, Portal 2 DLC #1 will be offered free of charge for the PC, Mac, Xbox 360, and PS3."

Source: RockPaperShotgun and Interlopers.net

EDIT - Oh snap, and Challenges are making a comeback! Hooray!

Quote:
The new DLC pack, entitled DLC #1, will be released this summer for the incredible price of free! The pack will include new test chambers, leaderboards, and challenge modes for both single and multiplayer. The DLC will be released for free on all platforms, so you can continue playing with your PS3 friends (if they're still using it after Sony's security leak fiasco).

Source: PC Gamer

Only a few days after release and the custom content community is already hard at work making new things to play with! We already have several uploads in the Portal 2 section of our already massive Download Database. Do you know someone who is making some custom maps? Point them here and get them uploaded!

Want to start making your own custom maps? Grab the Portal 2 Custom FGD by Omnicoder to start making science!

New Portal 2 stuff at the Valve store. I'm definitely picking up a few of these.

http://store.valvesoftware.com/new.php