It's all go at Payday: The Heist developer Overkill Software these days. As well as working on a sequel and DLC for its coop crime caper FPS, and being acquired by Starbreeze Studios, the Swedes have revealed they're working with Valve on something Left 4 Dead-y.

Read more: But what are they working on? »

It seems like Valve is committed to bringing its prized digital distribution service Steam to Linux users at some point in the relatively near future. Recent news indicates that Valve has not only hired Linux developers to help port Steam and the Source engine to the OS, but Valve's Gabe Newell is now overseeing the port.

Read more: Porting Steam and Source to Linux »

When Left 4 Dead first introduced its new brand of co-operative zombie-slaying, it didn't take long for a rabid fan-base to develop. In a recent interview, several Left 4 Dead luminaries, including writer Chet Faliszek and then-Turtle Rock CEO Mike Booth, reminisced about how the Left 4 Dead series came to be.

Read more: Making Left 4 Dead »

Valve's quest to inject original Left 4 Dead episodes into Left 4 Dead 2 continues. Today's Left 4 Dead 2 update includes the new version of the Terminal Map for Dead Air, the game's official blog revealed.

To entice people to test the update, the team at Valve is offering players a prize: the beta version of the Blood Harvest campaign for Left 4 Dead 2. Getting the prize won't be easy, however, as players will have to accomplish a difficult task together.

Read more: 60,000 achievements and counting »

Valve has been making comics around some of its biggest properties for months for free online, but now the company has partnered with Dark Horse Comics to bring them out in print. Comic Book Resources (via Gamasutra) reports that "Valve Presents: The Sacrifice and Other Steam-Powered Stories" will go on sale November 16 for $29.99.

The collection is a bit pricier than the average comic collection, but it's also more than three-hundred pages long and sports a hardcover. That makes it hard to complain. It will include stories from the worlds of Team Fortress 2, Portal, and Left 4 Dead. All indications are that this is a compilation of comics you can already find online, but it wouldn't surprise us if Valve slipped a bonus or two in there.

Last week, Valve promised to release the Left 4 Dead 2 version of classic Left 4 Dead episode 'Dead Air' if players helped beta test new community-made map Cold Stream, setting a target for 20,000 playthroughs. Good news! "You started playing at 10am on Wednesday morning. Four and half hours later you surpassed the 20,000 target," Valve revealed in a blog post. "By 5pm you passed 30,000. By this morning at 10am – a mere 24 hours later you hit 60,774!"

Read more »

Once again, Valve is offering early access to a game if its fans jump through a hoop or two. This time it's Left 4 Dead 2, and the offer is a piece of the Cold Stream downloadable content. A blog post outlines the details.

The developer is currently in the testing phase, and is offering an incentive for the community to become bug-finders. If 20,000 people earn the "Stream Crosser" achievement by the end of the day on Sunday, July 10, Valve will release Dead Air (from Cold Stream) on July 22. Stream Crosser is awarded for surviving a campaign of Cold Stream, so it shouldn't be too unobtainable. If you don't own the game yet, it's just $5 until 10 am PST today. Read more »

Last month, Valve announced that a new downloadable content pack was in the works that would port the three remaining campaigns from Left 4 Dead into the sequel, in addition to a new community-made campaign called 'Cold Stream.'

An announcement on the official Left 4 Dead blog today reveals that a beta for 'Cold Stream' has been released for the PC version of Left 4 Dead 2, via Steam. Those who like to hunt bugs along with their zombies are encouraged to dive in and give feedback to the developers via the Cold Stream forum. Read more »

A new Left 4 Dead 2 downloadable content pack is in the works, developer Valve has announced, featuring the three remaining Left 4 Dead campaigns that have yet to be ported over to the sequel as well as a new community-made campaign.

The new community campaign dubbed 'Cold Stream' is being made by Matthew Lourdelet, maker of '2 Evil Eyes,' which was Valve's first L4D2 featured campaign. Read more »

If you're a Half-Life (or Left 4 Dead) fan, and you haven't yet seen the recently released fan-made short film, Beyond Black Mesa, do yourself a favor.

We reached out to get some more information about how the project came together from Brian Curtin, who directed, produced, wrote, edited, acted, and art-directed the film, among other things. Making a high-quality fan-film on a shoestring budget (while working full-time) isn't an easy task, but Curtin and his cabal of film and Half-Life enthusiasts persevered to pull off one of the better bits of cinematic fan-fiction based on video games that we've seen to date. Read more »

Rock Band and Dance Central developer Harmonix has successfully been sold, former owner Viacom announced today, to itself--going privately-owned once again as an affiliate of investment firm Columbus Nova. Truly, it is a Festivus miracle!

"We're excited to be returning to our roots as an independent and privately owned studio," Harmonix wrote on its blog. "As for what it means for you, the DLC schedule marches on for Rock Band, we will continue our support of previously released titles and we're hard at work on some unannounced projects that we think you're going to be pumped about." Read more »

A group of ex-shareholders in Rock Band developer Harmonix, including several studio founders, are suing its parent company Viacom, Gamasutra reports, over allegedly attempting to avoid paying out performance-based bonuses for the rhythm game series.

When Viacom bought Harmonix back in 2006 for $175 million, it was agreed that Harmonix shareholders would be paid bonuses if the developer exceeded performance targets in 2007 and 2008. The ex-shareholders claim that they were never paid the 2008 bonus, which would have been based on any profit over $42 million. As the Rock Band franchise's retail sales were over $1 billion in 2008 and the first quarter of 2009, the profits and payouts were probably substantial. The plaintiffs are still calculating a figure. Read more »

Left 4 Dead's new DLC, 'The Sacrifice,' launched today, and in a move that's as much awesome as it is likely to cause some Xbox RAGE, Valve is selling both titles on Steam for a deep discount. The Mac version of Left 4 Dead 2 went live today as well, for the same ultra-low price.

Read more »

Valve is hoping to release the original Left 4 Dead on Mac "in time to celebrate Halloween," the developer revealed yesterday.

There's also a formal announcement that Left 4 Dead 2's Mac launch will coincide with the arrival of the L4D and L4D2 DLC 'The Sacrifice' on October 5--as has been known for a while. Read more »

The latest downloadable content for Left 4 Dead 2 (and presumably last for the original) is set to launch next week. "The Sacrifice" DLC follows the original Left 4 Dead cast as they journey South, losing one of their own team members along the way. While there is one real conclusion to the story, as evidenced in the previous DLC "The Passing," players will have the opportunity to re-write history and select which team member will fall in "The Sacrifice." It won't change the franchise's canon, but it'll make you look totally badass. Read more »