Valve has thrown a bit more of its weight behind Linux with the release of beta builds of Portal and Left 4 Dead 2. If you own either (or both) games you should find that beta versions have materialised in your Steam library - along with Portal 2, according to some. The Linux build of the first-person puzzler has so far gone unheralded by Valve, but here's a blog post describing the latest beta version of Left 4 Dead 2. In addition to letting Linux users play Valve's zombie hit, the download acts as a "testing ground" for its new Extended Mutation System. Thankfully, you can try the beta on Windows and Mac too.

The beta version of Left 4 Dead 2 is the same size as the main game, so you have a hefty download ahead of you. (I assume the same is true of Portal.) Steam for Linux officially launched in February, so it hasn't taken too long to get Portal and L4D2 on there. Half-Life 2 next?

Thanks to BluesNews and Kotaku.

Resident Evil 6 is out on PC starting today, and as announced by Capcom last week, it will feature PC zombie-slayers Coach, Ellis, Nick, and Rochelle from Left 4 Dead 2 in the exclusive Mercenaries No Mercy mode. A new trailer shows them doing what they do best, but the crossover hop seems to have bestowed the foursome with a repertoire of hilariously dramatic melee moves. There's no reason why the barrel-chested Coach would choose to shoulder-check through a horde before roll-diving away to blast an RPG at point blank, but damn if it isn't stylish.

You can grab Resident Evil 6 on Steam for $40. The L4D2 cross-over content will be available free April 5th.

Capcom announced today that Left 4 Dead 2's Coach, Nick, Ellis, and Rochelle will be playable in Resident Evil 6's PC-exclusive Mercenaries No Mercy multiplayer mode, and in the other direction, three of Resident Evil 6's zombies will shuffle into the PC version of Left 4 Dead 2. The crossover, which is being called "the Resident Evil 6 x Left 4 Dead 2 project" (Capcom's idea, we presume) will be free for both games later this spring.

In addition to L4D2's human characters, the Witch and Mini Tank will "make a cameo appearance" in Mercenaries No Mercy, though it isn't clear whether or not the mercenaries will have any mercy. I think they might, but something about it makes me unsure. As for L4D2, Resident Evil 6 offers Lepotitsa, Napad, and Ogroman, which have been "brought to life in Left 4 Dead 2 by Valve’s renowned developers."

In Resident Evil 6, which releases for PC on March 22, the content will "automatically be downloaded in the background" starting April 5th, and the Left 4 Dead 2 content will be available sometime this spring through Steam Workshop.

For Rohan! Valve's Left 4 Dead team writes that Left 4 Dead 2 servers now run Team Chivalry and SeriouS Samurai's LOTR-inspired Survival mode map by default for players who subscribe to the map's Workshop entry. It's a celebratory move for a recent dedicated server fix and the ongoing beta for the Extended Mutation System, but c'mon—do you really need a reason to defend a massive stone fortress against waves of Saruman's mightiest undead?

I haven't run for my life in Left 4 Dead 2 in quite a while, but awaiting rescue from Gandalf while possibly yelling "AND MY CHAINSAW" into my microphone sounds like just the kind of fun to hook me back in.

In a first for the company, Valve let go an unspecified number of employees across multiple teams including hardware and Android development, according to a report by Gamasutra.

Valve hasn't released official word on the number of departures or how this affects its Steam Box project, but Gamasutra says it's hearing such descriptions as "great cleansing" and "large decisions" from those let go. "We've seen the number '25' tossed around, but are unable to confirm this," the Gamasutra article claims.

Yesterday, hardware hacker Jeri Ellsworth, who was hired by Valve to join its hardware team, tweeted a sudden announcement that she'd been fired and was moving on to "new and exciting projects." Elsewhere, the LinkedIn profile of Ed Owen, a senior mechanical engineer, shows an end employment date of February 2013 at Valve.

Though layoffs happen from time to time in the industry, Valve's reputation as one of the most secretive (and lucrative) studios in the business underscores the peculiarity of this development, especially when the terms "layoffs" and "fired" aren't normally associated with a company known for its free-form work philosophy.

We've reached out to Valve for an explanation and for further confirmation about how many people have been let go. We'll update this story if more information arrives today.

UPDATE: Garry's Mod creator Garry Newman tweets the appearance of a number of differences on Valve's staff page seen through Diff Checker. The comparison tool indicates the removal of nine employee bios from the People section of Valve's company page, listed below:

Moby Francke, Half-Life 2 character designer and Team Fortress 2 art lead
Jason Holtman, director of business development for Steam and Steamworks
Keith Huggins, character animator and animator for Team Fortress 2 "Meet the" video series
Tom Leonard, software engineer for Half-Life 2 and Left 4 Dead
Realm Lovejoy, artist for Half-Life 2, Portal, and Left 4 Dead. She was also part of the original DigiPen-turned-Valve team that created Narbacular Drop, the inspiration for Portal
Marc Nagel, test lead for Half-Life, Counter-Strike, and patch updates
Bay Raitt, animator for Half-Life 2, Team Fortress 2, and Portal
Elan Ruskin, engine programmer for Left 4 Dead, Portal 2, and Counter-Strike: Global Offensive
Matthew Russell, animator for Team Fortress 2 "Meet the" video series


UPDATE: Valve boss Gabe Newell sent along his response to Engadget: "We don't usually talk about personnel matters for a number of reasons. There seems to be an unusual amount of speculation about some recent changes here, so I thought I'd take the unusual step of addressing them. No, we aren't canceling any projects. No, we aren't changing any priorities or projects we've been discussing. No, this isn't about Steam or Linux or hardware or . We're not going to discuss why anyone in particular is or isn't working here."

The extent of Left 4 Dead 2's mods already defies description, where the truly wacky shambles alongside the horde of new weapons and campaigns. Now, Valve wants to further slash at the barrier between a modder's creativity and what's possible in-game with the Extended Mutation System, an expanded scripting toolset and the future name of my progressive rock band.

As Valve explains it, the system "allows script authors to go past modifying existing scripts and write custom script logic, spawn and control entities, and much more." Think of entirely new game modes, a restructured Director, or custom HUDs. One of Valve's examples was a mode called Holdout that has survivors buying and erecting barricades against waves of undead similar to Call of Duty's Zombies spin-off.

The Extended Mutation System is in beta testing for now, but Valve's developer wiki already provides a few initial walkthroughs for sample custom modes. I'm keen on GnomeHunter—a CTF-meets-hot-potato mode where players have to lug that infernal garden gnome to a locker—but I'd love seeing a variation of Team Fortress 2's Prop Hunt in Versus mode. Why? Because the Hunter can't smell me if I'm a safety cone. Make it happen, modders!

As if slaying your way across a zombie-infested wasteland as a pack of gun-toting raptors wasn't awesome enough, modder Lurch of the L4DMaps community offers the Stay Puft mod which replaces Left 4 Dead 2's burly Tank with the soft and tasty juggernaut from Ghostbusters.

It's a pretty basic mod—a simple reskin of the Tank is all you'll get for less than a megabyte's download. Some default animations don't exactly translate well in those rolls of sugary goodness, as the model's arms stick out awkwardly and ragdoll effects are anything but smooth. Rock tosses are subsequently hilarious-looking. (You'll see what I mean in the short video I recorded above.) Still, making the conscious decision to shoot at and be chased by a grunting behemoth of marshmallow should count for something.

You can pick up Puft at L4DMaps' website. Be sure to also check out Left 4 Dead 2's freshly launched Steam Workshop listing for more mods.

Valve have posted a patch for Left 4 Dead 2 this morning. Along with the regular old incomprehensible patch notes, ("Cleaned up DLC add-on file dependencies and simplified talker file structure." Huh?) they've finally enabled Steam Workshop support, creating an easy system for browsing and installing new weapons, campaigns, items and - er - clothing. I guess the Venn diagram of fashion enthusiasts and mod creators does have some crossover.

As it's only been live for a few hours, L4D2's Workshop listing is still a bit barren. It shouldn't take long for some top content to appear, though - Left 4 Dead 2 already has a healthy modding community, so, with any luck, some of the best will be uploaded in the coming days.

Adding mods to the game was already a relatively simple process, but of course the Workshop streamlines it down further and, perhaps more importantly, will automatically each mod with any patch the creator uploads.

Hopefully we'll soon see some of the great community created campaigns start to appear, like these brilliant Back 2 School maps.

Australia's newly minted R18+ rating for video games is starting to work its magic. In a post on the Steam Forums, Valve's Chet Faliszek has confirmed the company is "exploring options" for resubmitting Left 4 Dead 2 for classification in Australia, where it was released as a censored version in 2009. Of course, enterprising and bloodthirsty Australians simply opted to order a copy from overseas, but technically that's illegal. Now, there's a chance you'll be able to inflict gratuitous harm safe from prosecution.

According to the post on the Steam forums, Faliszek said the company was on the case. "We have been exploring the options here and what we can legally do," he wrote. "We will have more information on this when we understand the issues fully and how we are moving forward, but don't worry, any cost associated with it doesn't worry us, this is something we want to do."

The Australian Classification Board introduced the new R18+ rating on January 1. Since then, Ninja Gaiden 3: Razor's Edge for the Wii U has been the first to earn the rating, while Warner Bros has confirmed they will resubmit the previously banned Mortal Kombat for classification.

Someday, Valve will eventually run out of wonderful features to pack into its mega-gaming-hub Steam. Let's hope it's a long way off, because we'll all be busy poring over the user-written manuals, walkthroughs, and tips for our various games in the newly launched Steam Guides section of Steam's Community area.

Anyone can create and submit a guide for the game of their choice by clicking the new Guide tab on a game's Community Hub page. You can pretty up your words with images and embedded YouTube videos as well, and the guides also appear upon Steam's overlay whenever you're running a program. Neat. I can finally whip up my "How to avoid tigers" guide I've been planning for Far Cry 3 quickly and easily.

Head over to the Steam Guides page to take a look at the over 1,000 guides already created.