Valve’s work on Left 4 Dead has paid off, as the studio announced that the cooperative shooter has now sold over 2.5 million copies since its debut in November 2008.

This news came as part of project lead Michael Booth’s GDC presentation on the game. The figure includes both PC and Xbox 360 releases, but does not include sales from the company’s digital distribution platform Steam. The numbers would be higher of course, and it should be pointed out that a recent discount saw sales jump 3000%.

A new patch for Team Fortress 2 officially adds multicore rendering support, allowing users with dual core and quad core CPUs to take better advantage of the money they spent on their computers.

It was a hidden console command at first, but even though it is now official and included in the GUI, Valve notes that it is testing the compatibility of the feature, so the option is turned off by default. You will have to manually enable the option in the game’s menu.

Other changes in the patch include crash fixes, improvements to the engine and more.

Valve today announced that the first in-game DLC has hit Steam in the form of two expansion levels for The Maw.

Publishers can now sell their content from within the game rather than only through Steam’s storefront.

"DLC can now be added to any game on Steam, regardless of whether it was originally purchased via Steam, at retail, or via other digital outlets," the company stated. "It is also a feature of Steamworks, the suite of free tools and services available to game developers and publishers."

The two levels are “Brute Force” and “River Redirect”, both of which are now available for purchase for $1.25 each.

Following last week’s tease that it would hit the digital distribution platform, Criterion’s open-world racer Burnout Paradise is now on Steam. The download is priced at $39.99, the same as the retail version.

The PC version was released early last month. It features enhanced graphics and all of the downloadable content that has so far been released for the consoles, including the offline multiplayer Party pack.

Following up on its cryptic announcement last week, Valve has released a few details on the Survival Pack DLC for Left 4 Dead.

The new Survival mode will let “up to four players set records for the longest time surviving hordes of zombies on over 12 maps,” according to this GameTrailers TV video. It wasn’t specified whether those maps will be all-new or the current ones.

The pack will also include Versus Mode versions of the Dead Air and Death Toll campaigns. It is set for release this spring.

Celebrating the 10th anniversary of the release of the original Half-Life, and to celebrate the decade since the birth of the beloved shooter franchise, Valve is selling the game that started it all for only 98 cents.

Yes, you read that right: Half-Life for 98 cents. This offer is valid till tomorrow, so if you want to get into the franchise, now is the time to do so.

Expanding your purchase options, Call of Duty: World at War is now available on Steam.

Developed by Treyarch, the game is now selling like hotcakes across all regions. It can be bought for $49.95, the same price as retail.

Left 4 Dead is composed of four movie-sized acts that are introduced by loading screen art done in a sort of film one-sheet poster, complete with campy lines and full credit list.

These posters have been released by Valve as downloadable images. Check them out below. The game itself is due out in three days.

None can deny the stylish, filmic look of Left 4 Dead, Valve’s latest release. The studio has released details on the post-processing effects it has used to give the game that effect, which makes it stand out from all the other titles in the market, and also gives the game that stylish look which has become its trademark.

Some of these effects include film grain, vignetting and local contrast, all of which are known to photographers at the very least. Be sure to check out the post, cause it’s an interesting read.

In anticipation of the game’s release on November 18 on PC and Xbox 360, Valve has released the introduction trailer for its cooperative zombie shooter Left 4 Dead.

The four-minute video was produced entirely using the game’s engine; it was created by the same team that produced the popular Team Fortress 2 “Meet the…” videos.

Shacknews carries word from Valve marketing director Doug Lombardi that downloadable content is in the pipeline for the Xbox 360 version of Team Fortress 2.

“We’re looking at bringing the Goldrush and the new achievements and stuff out to the 360,” Lombardi is quoted as saying. “How and when is still sort of being determined, on pricing and that kind of stuff. On the PC it’s sort of wide open, you can release stuff whenever you want. On the console there’s a little bit more of a pathway.”

Lombardi further noted that they have been waiting for a “critical mass of new content” before releasing something for the console. He hopes that the company will make announcements soon, though he wouldn’t offer any definite date. He also states that he “doesn’t know” if the DLC will be released for the PS3 or not.

Shacknews reports that Valve will release two new maps for Team Fortress 2 within the next two months. One of them is a remake of the original’s Badlands map, which places an emphasis on more vertically-oriented gameplay. No information was disclosed on the other map.

The studio will also release a Medic achievement pack, which will add several new achievements for the Medic class as well as make significant gameplay tweaks to that particular class. Apparently, more new content will debut eventually that will make “large scale modifications” to the core of the game.

The site carries clarification that the new maps will be released for the PC version of the game. It is not known if the maps will be available for the PS3 and Xbox 360 versions of the game.

Valve announced that it has acquired Turtle Rock Studios, the Orange County-based development studio behind portions of Counter-Strike: Condition Zero, various Counter-Strike maps and the upcoming Left 4 Dead game.

The studio’s Left 4 Dead joins Valve’s game properties which includes the blockbuster Half-Life franchise, Counter-Strike, Team Fortress and Day of Defeat series of games, as well as Portal.

“We have been seeing very strong growth with Steam and Source, our content distribution and development platforms, up over 150% over the last 12 months. Given our expectations for Left 4 Dead and our long-standing relationships with members of the Turtle Rock team, this was an easy decision. It also gives us a base from which to expand our development activities in the Los Angeles area,” said Gabe Newell, president of Valve.

Left 4 Dead is now expected to be released this Summer on PC.

Gamers can now gift games to other users on Steam – be it a friend, family or a random stranger. The recipient will receive the game with a special message from the sender. This page has more details about gift purchases on Valve’s broadband delivery service.

AMD/ATI fans are in luck, as the company announced that owners of ATI Radeon graphic card owners are entitled to a pair of free games from Steam, Valve’s content delivery service. Eligible gamers can visit this page for details on how to get free copies of Half-Life 2: Lost Coast and Half-Life 2: Deathmatch as well as discounts on other Valve games.