Lobby area of Valve's offices in Bellevue, Washington
|Headquarters||Bellevue, Washington, United States|
Number of locations
|Total equity||US$2.5 billion (2012)|
Number of employees
Valve Corporation (formerly Valve L.L.C., commonly referred to as Valve, stylized as VALVE) is an American video game developer and digital distribution company headquartered in Bellevue, Washington. Its Luxembourg-based business office subsidiary for European regions, Valve S.a.r.l, was opened in 2012. Founded in 1996 as Valve L.L.C. by former Microsoft employees Gabe Newell and Mike Harrington, the company has developed the critically acclaimed Half-Life, Counter-Strike, Portal, Day of Defeat, Team Fortress, Left 4 Dead video game series, alongside Dota 2. It also developed and maintains Source on which most of its games run, and the software distribution platform Steam, which has led to the Steam Machine, a line of pre-built gaming computers running SteamOS.
- 1 History
- 1.1 Founding and incorporation
- 1.2 Half-Life
- 1.3 Source game engine
- 1.4 Acquisitions and awards
- 1.5 Network intrusions
- 1.6 Legal disputes
- 1.6.1 Valve Corporation v. Vivendi Universal Games
- 1.6.2 Valve Corporation v. Activision Blizzard
- 1.6.3 Blizzard Entertainment v. Valve Corporation
- 1.6.4 ACCC v. Valve Corporation
- 1.6.5 UFC Que Choisir v. Valve Corporation
- 1.6.6 A.M. v. Valve Corporation
- 1.6.7 Counter-Strike: Global Offensive skins gambling
- 2 Games
- 3 Other ongoing projects
- 4 Organizational structure
- 5 "Valve Time"
- 6 PowerPlay
- 7 References
- 8 External links
Founding and incorporation
Valve was founded by former longtime Microsoft employees Gabe Newell and Mike Harrington on August 24, 1996, as Valve L.L.C., based in Kirkland, Washington on the Seattle Eastside. Harrington left the company in 2000. After incorporation in April 2003, it moved from its original location to Bellevue, Washington, the same city in which their original publisher, Sierra On-Line, Inc., was based. In 2010, the office was moved again to a larger location in Bellevue, WA.
After securing a license to the Quake engine through the help of friend Michael Abrash of id Software in late 1996, Newell and Harrington began working on Half-Life. Originally planned for release in late 1997, Half-Life launched on November 19, 1998. Valve acquired TF Software PTY Ltd, the makers of the Team Fortress mod for Quake, in May 1998 with the intent to create a standalone Team Fortress game. The Team Fortress Classic mod, essentially a port of the original Team Fortress mod for Quake, was released for Half-Life in 1999. Gearbox contributed much after the release of Half-Life. Gearbox Software is responsible for the Half-Life expansion packs, Half-Life: Opposing Force and Half-Life: Blue Shift, along with the home console versions of Half-Life for the Sega Dreamcast and Sony PlayStation 2 which included a third expansion pack called Half-Life: Decay, that enabled two-player split-screen co-op.
Source game engine
After the success of Half-Life, the team worked on mods, spin-offs, and sequels, including Half-Life 2. All current Valve games are built on its Source engine. The company has developed six game series: Half-Life, Team Fortress, Portal, Counter-Strike, Left 4 Dead and Day of Defeat. Valve is noted for its support of its games' modding community: most prominently, Counter-Strike, Team Fortress, and Day of Defeat. Valve has branched out with this tradition to continue developing Dota 2 as the standalone sequel to the Warcraft III mod. Each of these games began as a third-party mod that Valve purchased and developed into a full game. They also distribute community mods on Steam. Valve announced the Source 2 engine on March 3, 2015.
Acquisitions and awards
Valve has grown both in scope and commercial value. On January 10, 2008, Valve announced the acquisition of Turtle Rock Studios. On April 8, 2010, Valve won The Escapist Magazine's March Mayhem tournament for the best developer of 2010, beating out Zynga in the semi-finals and BioWare in the final.
In 2012, the company acquired Star Filled Studios, a two-man gaming company to open a San Francisco office. In August 2013, however, Valve ended the operation when it was decided that there was little benefit coming from the arrangement.
Valve's internal network has been infiltrated by hackers three times, once in 2003 where content of yet to be released Half-Life 2 was leaked onto the internet, Newell's email account was compromised, and keyloggers were installed on several Valve systems. In 2011 the Steam customer databases and official forums were compromised. On September 2011, a hacker broke into the network and downloaded the yet to be released beta code of Call of Duty: Modern Warfare 3.
In 2014, a developer from SCS Software reported an exploit that allowed announcement pages to be injected with code, and after no response, he edited an announcement to redirect users to a Harlem Shake (meme) video. In 2016, a vulnerability on the Steam Store allowed a user to publish a game without any authorization from Valve.
Valve Corporation v. Vivendi Universal Games
Between 2002 and 2005, Valve was involved in a complex legal showdown with its publisher, Vivendi Universal Games (under Vivendi's brand Sierra Entertainment). It officially began on August 14, 2002, when Valve sued Sierra for copyright infringement, alleging that the publisher illegally distributed copies of their games to Internet cafes. They later added claims of breach of contract, accusing their publisher of withholding royalties and delaying the release of Counter-Strike: Condition Zero until after the holiday season.
Vivendi fought back, saying that Gabe Newell and marketing director Doug Lombardi had misrepresented Valve's position in meetings with the publisher. Vivendi later countersued, claiming that Valve's Steam content distribution system attempted to circumvent their publishing agreement. Vivendi sought intellectual property rights to Half-Life and a ruling preventing Valve from using Steam to distribute Half-Life 2.
On November 29, 2004, Judge Thomas Samuel Zilly of the U.S. District Court for the Western District of Washington ruled in favor of Valve. Specifically, the ruling stated that Vivendi Universal and its affiliates (including Sierra) were not authorized to distribute Valve games, either directly or indirectly, through cyber cafés to end users for pay-to-play activities pursuant to the parties' publishing agreement. In addition, Judge Zilly ruled that Valve could recover copyright damages for infringements without regard to the publishing agreement's limitation of liability clause. Valve posted on the Steam website that the two companies had come to a settlement in court on April 29, 2005. Electronic Arts announced on July 18, 2005, they would be teaming up with Valve in a multi-year deal to distribute their games, replacing Vivendi Universal from then onwards. As a result of the trial, the arbitrator also awarded Valve $2,391,932.
Valve Corporation v. Activision Blizzard
In April 2009, Valve sued Activision Blizzard, which acquired Sierra Entertainment after a merger with its parent company, Vivendi Universal Games. Activision had allegedly refused to honor the Valve v. Vivendi arbitration agreement. Activision had only paid Valve $1,967,796 of the $2,391,932 award, refusing to pay the remaining $424,136 claiming it had overpaid that sum in the past years.
Blizzard Entertainment v. Valve Corporation
Shortly after Valve filed its trademark for "Dota" to secure the franchising rights for Dota 2, DotA-Allstars, LLC, run by former contributors to the game's predecessor, Defense of the Ancients, filed an opposing trademark in August 2010. DotA-Allstars, LLC was sold to Blizzard Entertainment, the developer of DotA's platform Warcraft III and its world editor, in 2011. After the opposition was overruled in Valve's favor, Blizzard itself filed an opposition against Valve in November 2011, citing their license agreement with developers, as well as their ownership of DotA-Allstars, LLC. On May 11, 2012, Blizzard and Valve announced that the dispute had been settled. Valve retained the rights to the term "Dota" commercially, while Blizzard reserved the right for fans to use the trademark non-commercially, and changed the name of their StarCraft II map, Blizzard DOTA, to "Blizzard All-Stars". Blizzard All-Stars was adapted into a standalone game and renamed "Heroes of the Storm" on October 17, 2013.
ACCC v. Valve Corporation
- consumers were not entitled to a refund for digitally downloaded games purchased from Valve via the Steam website or Steam Client (in any circumstances);
- Valve had excluded statutory guarantees and/or warranties that goods would be of acceptable quality; and
- Valve had restricted or modified statutory guarantees and/or warranties of acceptable quality.
A hearing is scheduled for October 5, 2016 to decide on action.
UFC Que Choisir v. Valve Corporation
A.M. v. Valve Corporation
Counter-Strike: Global Offensive skins gambling
Valve was named in a defendant in two lawsuits in June and July 2016 related to third-party gambling sites that use the Steamworks API to allow betting with the virtual currency of cosmetic weapon "skins" from Counter-Strike: Global Offensive, which through these sites can be converted from or to real-world money. Both suits assert Valve aiding in underaged gambling. Valve subsequently stated it has no commercial ties with these sites, and that it would demand these sites cease their use of the Steamworks API as they violate the authorized use policies.
Valve worked with Arkane Studios on The Crossing, which was canceled in May 2009. Arkane later tried to produce Return to Ravenholm (a.k.a. Half-Life 2: Episode Four) without consensus by Valve, which was then also canceled.
Other ongoing projects
Valve announced its games platform Steam in 2002. At the time it looked merely to be a method of streamlining the patch process common in online video games, but was later revealed as a replacement for much of the framework of the World Opponent Network service and also as a distribution/digital rights management system for entire games.
As of July 2014, there are over 3,400 games available on Steam, and in January 2014 Valve announced that it had surpassed 75 million active user accounts.
Alongside these changes to the SSA, the company also declared publicly the incorporation of Valve S.a.r.l., a subsidiary based in Luxembourg. Valve set up a physical office in Luxembourg Kirchberg, according to Valve's project manager Mike Dunkle, the location was chosen for eCommerce capabilities and infrastructure, talent acquisition, tax advantages and its central geographic locations – most major partners are accessible with 50% within driving distance.
Valve S.a.r.l is used to sell games to United Kingdom–based users to avoid paying the full 20% VAT. The tax loophole was expected to be closed on January 1, 2015. In December 2015, the French consumer group UFC Que Choisir initiated a lawsuit against Valve for several of their Steam policies that conflict or run afoul of French law. One of the reasons was for using the tax loophole.
Newell has been critical of the direction that Microsoft has taken with the Windows operating system in making it a closed architecture similar to Apple's products, and has stated that he believes that with changes made in Windows 8 are "a catastrophe for everyone in the PC space". Newell identified the open-source Linux platform as an ideal platform for Steam, noting that the only thing holding back its adoption is the lack of games.
In 2012, Valve announced that they were working on a console/PC hybrid for the living room which was unofficially dubbed by media as the "Steam Box". A precursor to such a unit is SteamOS, a freely available Linux-based operating system that builds upon the Steam client functionality that includes media services, live streaming across home networks, game sharing within families, and parental controls. SteamOS was officially announced in September 2013 as the first of several announcements related to the Steam Machine platform as well as their unique game controller. In early Summer 2014, Valve announced that the company's own SteamOS-powered Steam Machine would be delayed until 2015 due to problems with the game controller.
In July 2013, Valve officially announced Pipeline, an intern project consisting of ten high school students working together to learn how to create video game content. Pipeline serves a dual purpose:
- to discuss and answer questions that teenagers often ask about the video game industry
- to see if it is possible to train a group of teenagers with minimal work experience to work for a company like Valve
J. J. Abrams collaboration
In March 2015, Valve and HTC announced a joint project to develop Vive, a head-mounted virtual reality display. The companies are working with Google, Lions Gate, and HBO to develop content for the device.
Valve is run as a flat organization without bosses, and uses open allocation (employees can move between teams at will). Economist Yanis Varoufakis, a former economic consultant for Valve, and former Finance Minister of Greece, attempted to place Valve's organization in the context of theories of the firm and broader economic thinking. Former employee Jeri Ellsworth has, however, criticized the structure as "a lot like high school", where while the structure is flat, certain people within the company nevertheless have more say in decisions than others.
"Valve Time" is an industry term used jokingly with game releases from Valve, used to acknowledge the difference between the "promised" date for released content stated by Valve and to the "actual" release date; "Valve Time" includes predominant delays but also includes some content that was released earlier than expected. Valve itself has fully acknowledged the term, including tracking known discrepancies between ideal and actual releases on their public development wiki and using it in announcements about such delays. Valve ascribes delays to their mentality of team-driven initiatives over corporate deadlines to make sure they provide a high-quality product to their customers.
Valve's former business development chief Jason Holtman stated that the company sees themselves as an "oddity" in an industry that looks towards punctual delivery of products; instead, Valve "[tries] as hard as we can to make the best thing possible in the right time frame and get people content they want to consume. And if that takes longer, that's fine". For that, Valve takes the concept of "Valve Time" as a compliment, and that "having customers consistently looking at our property or something you've done and saying, can you give me more" is evidence that they are making the right decisions with their game releases, according to Holtman. The company does try to avoid unintentional delays of their projects, and believes that the earlier occurrences of "Valve Time" delays, primarily from Half-Life development, has helped them improve their release schedules.
PowerPlay was a technological initiative headed by Valve and Cisco Systems to decrease the latency for online computer games. Gabe Newell, the managing director of Valve, announced the project in January 2000 and after 12 months the project was quietly abandoned.
PowerPlay was described as a set of protocols and deployment standards at the router level to improve performance. It was claimed that a player with 1000 ms ping was able to play against another player on a LAN connection with no noticeable disadvantage. Initially the protocol was to be released with PowerPlay 1.0 focusing on Quality of Service (QoS) and later a revision, PowerPlay 2.0 that would focus on functionality. Cisco and Valve intended to deliver a single dial-up service in Q1 2000 in the United States with a 30-day free trial with a bundled copy of Team Fortress modified to support PowerPlay. Despite never deploying the dial-up plan featuring PowerPlay 1.0, Valve announced in January 2001 that the standard had indeed been finalized.
The standard was to involve purchasing PowerPlay approved Cisco hardware and infrastructure that had adequate bandwidth and QoS standards that prioritize PowerPlay gaming packets at the expense of all others. Gabe Newell conceded that Internet service providers (ISPs) would bear the brunt of this expense: "The ISPs are going to need to spend a fair amount of money to be compliant with PowerPlay. But how they get that back is up to them. Some will have a tiered service, and some will just try to recoup their investment through reduced customer churn and customer acquisition."
- Wingfield, Nick (September 8, 2012). "Game Maker Without a Rule Book". The New York Times. Retrieved September 9, 2012.
- Dudley, Brier (November 4, 2013). "A glimpse of Valve's Steam Machine, controller design and hardware plans". Seattle Times. Retrieved November 4, 2013.
- "Steam Message". Steam. Valve Corporation. August 24, 2007. Retrieved November 8, 2008.
it was exactly eleven years ago that Valve was born
- Towns, William R. (March 9, 2005). "Valve Corporation v. ValveNET, Inc., ValveNET, Inc., Charles Morrin Case No. D2005-0038". WIPO Arbitration and Mediation Center. World Intellectual Property Organization. Retrieved November 8, 2008.
- "Washington Secretary of State". Retrieved April 25, 2010.
- "Valve Handbook for New Employees" (PDF). Valve Corporation. Retrieved September 1, 2013.
- Levy, Nat (August 3, 2016). "Valve leases nine floors in planned skyscraper, more than doubling its headquarters size". GeekWire. Retrieved August 3, 2016.
- "Team Fortress Full Speed Ahead". GameSpot. Retrieved 2 June 2016.
- Biessener, Adam (October 13, 2010). "Valve's New Game Announced, Detailed: Dota 2". Game Informer. Retrieved October 8, 2012.
- "Source Filmmaker". Source Filmmaker. Retrieved March 31, 2013.
- Langley, Hugh (March 3, 2015). "Valve just announced its plans for Steam Machines... and Source 2". Tech Radar. Retrieved March 3, 2015.
- "Valve Acquires Turtle Rock Studios" (Press release). Valve Corporation. January 10, 2008. Retrieved January 10, 2008.
- Palumbo, Jeff (April 8, 2010). "Valve Becomes the New March Mayhem: Developer's Showdown Champion". escapistmagazine.com. Retrieved April 24, 2010.
- Hing, David (December 17, 2012). "Valve acquires or hires Star Filled Studios". bit-gamer.net. Bit-tech.net. Retrieved August 31, 2013.
- Reilly, Luke (August 7, 2013). "Valve's San Francisco Remote Office Shut Down". IGN.
- "Playable Version of Half-Life 2 Stolen". CNN Money. October 7, 2003. Retrieved February 14, 2007.
- Johnson, Casey (November 10, 2011). "Valve confirms Steam hack: credit cards, personal info may be stolen". Ars Technica. Retrieved November 10, 2011.
- Leyden, John (November 9, 2011). "Steam games forum down amid hack fears". The Register. Retrieved November 10, 2011.
- Totilo, Stephen (September 30, 2014). "Hackers Charged With Stealing From Valve, Microsoft And More". Kotaku. Gawker Media. Retrieved October 31, 2015.
- Frederiksen, Eric (October 4, 2014). "Hackers Charged with Theft from Studios Like Microsoft, Valve and Epic". TechnoBuffalo. Retrieved October 31, 2015.
- Feldman, Curt (September 20, 2004). "Valve vs. Vivendi Universal dogfight heats up in US District Court". GameSpot. CNET Networks, Inc. Retrieved November 8, 2008.
- "Valve and Vivendi Universal Games Settle Lawsuit" (Press release). Valve Corporation. April 29, 2005. Retrieved November 8, 2008.
- "EA and Valve Team Up to Deliver Half Life to Gamers Worldwide". Electronic Arts Inc. July 18, 2005. Retrieved November 8, 2008.
- "It's Ugly: Valve Sues Activision, Activision Threatens to Sue Valve". gamepolitics.com. April 30, 2009. Retrieved May 1, 2009.
Against that backdrop, Activision cut Valve a check last week for $1,967,796—the amount handed down by the arbitrator less the disputed $424K. According to Valve's suit, Activision said that it wouldn't pay the rest and if Valve went to court Activision would countersue. Valve has apparently called Activision's bluff and the parties are now once again at odds.
- "Valve Corporation v. Activision Blizzard, Inc.". United States Court of Appeals, Ninth Circuit. July 30, 2010.
- Augustine, Josh (August 17, 2010). "Riot Games' dev counter-files "DotA" trademark". PC Gamer. Retrieved August 19, 2011.
- Plunkett, Luke (February 10, 2012). "Blizzard and Valve go to War Over DOTA Name". Kotaku.
- Reilly, Jim (May 11, 2012). "Valve, Blizzard Reach DOTA Trademark Agreement". Game Informer.
- Narcisse, Evan (October 17, 2013). "Blizzard's Diablo/Starcraft/WoW Crossover Has a New Name". Kotaku.
- Sarkar, Samit (July 11, 2016). "How do Counter-Strike: Global Offensive skins work?". Polygon. Retrieved July 11, 2016.
- Francis, Bryant (July 13, 2016). "Valve says it will start cracking down on third-party gambling sites". Gamasutra. Retrieved July 13, 2016.
- "News - In-Game Item Trading Update". store.steampowered.com. Retrieved 2016-07-15.
- "Valve were making a fairy RPG before Left 4 Dead | Interviews, News". PC Gamer. Retrieved March 23, 2013.
- Half-Life 2: Raising the Bar. Prima Games. 2004. p. 10. ISBN 0-7615-4364-3.
- "Valve SOB Project Was Called 'Stars of Blood'". ValveTime.net. November 11, 2012.
- "Gabe Newell On Valve's "SOB": "'Stars of Blood' Was An Internal Project That Never Saw The Light of Day"". LambdaGeneration. November 12, 2012.
- "Marc Laidlaw On The Cancelled Half-Life Spin-offs: Return To Ravenholm And "Episode Four"". LambdaGeneration. January 13, 2012. Archived from the original on January 16, 2012. Retrieved July 19, 2013.
- Savage, Phil (January 15, 2013). "Half-Life 2: Episode 4 was being developed by Arkane; now cancelled". PC Gamer. Retrieved July 8, 2014.
- O'Conner, Alice (May 15, 2009). "Arkane and Valve's 'The Crossing' on Hold". Shacknews. Retrieved June 11, 2013.
- "Steam has 75 million active users, Valve announces at Dev Days". Joystiq. January 15, 2014. Retrieved July 11, 2014.
- "Steam's Sub Agreement Prohibits Class-Action Lawsuits". Rock, Paper, Shotgun. August 1, 2012. Retrieved August 3, 2012.
- "Updated Steam Subscriber Agreement". Valve Corporation. August 1, 2012. Retrieved August 3, 2012.
- Valve Software Latest Gaming Company to Set Up in Luxembourg. Chronicle.lu (September 4, 2012). Retrieved on 2014-05-23.
- Karmali, Luke. (March 25, 2014) Steam, Amazon and iTunes Prices Could Rise in UK. IGN. Retrieved on 2014-05-23.
- Chapple, Craig. (March 25, 2014) UK closing tax loophole on Steam game downloads | Latest news from the game development industry | Develop. Develop-online.net. Retrieved on 2014-05-23.
- Nutt, Christian (December 17, 2015). "French consumer group sues Valve over Steam policies". Gamasutra. Retrieved December 17, 2015.
- Crabtree, Dan (July 25, 2012). "Gabe Newell: "Windows 8 Is Kind of a Catastrophe"". IGN. Retrieved September 24, 2013.
- Davies, Marsh (December 9, 2012). "Valve confirms Steam Box – a "very controlled" PC for the living room". PC Gamer. Retrieved April 21, 2013.
- Newman, Jared (March 18, 2013). "Valve's Steam Box: The plot thickens for PC-based game consoles". PC World. Retrieved April 21, 2013.
- Kohler, Chris (September 23, 2013). "Valve Continues Its War on Game Consoles With Steam Operating System". Wired. Retrieved September 23, 2013.
- Vaughn-Nichols, Steven J. (May 28, 2014). "Valve Steam Machines delayed until 2015". ZDNet. Retrieved June 3, 2014.
- "Pipeline — About Us". Valve Corporation. Retrieved September 13, 2013.
- "Pipeline — Home". pipeline.valvesoftware.com. Valve Corporation. Archived from the original on August 20, 2014. Retrieved August 31, 2013.
Why is Valve doing this? There are two main reasons that Valve is creating Pipeline. The first is that we are frequently asked questions by teenagers about the videogame industry. "What is it like to work on videogames? What should I study? What colleges are best for preparing me? How do I get a job in videogames?" Pipeline will be a place where those questions can be discussed. The second is that Valve is running an experiment. Traditionally Valve has been a very good place for very experienced videogame developers, and not so good at teaching people straight out of school (the reasons for this and the tradeoffs are covered in the Valve employee handbook). Pipeline is an experiment to see if we can take a group of high school students with minimal work experience and train them in the skills and methods necessary to be successful at a company like Valve.
What is the objective of the website itself? We want to establish a connection to the world of teenagers that are asking many questions about getting into the gaming industry. We look to answer many of these questions and are willing to reach out to the community and give them the information they need.
Why Pipeline? The name 'Pipeline' was chosen for its industrial connection with names like Valve and Steam, as well as its definition's notion of connection, direction, outreach, and supply. Valve is often asked questions such as "how do I get from where I am now to working at a professional level in a video game company like Valve?" Naturally, like a pipeline, the journey is long, but the goal of this project is to act as a direct feed of knowledge from Valve to the community in order to help equip individuals with the skills necessary to achieve their goals of getting into the video game industry. We will supply information on a variety of different fields prompted by public demand. Information will come in the form of interviews with professionals and resources on this website, displaying the variety of ways that you can achieve your goals.
- "LambdaGeneration 2.0 - Coming Soon". Lambdageneration.com. Retrieved August 31, 2013.
- Good, Owen S. (March 1, 2015). "Valve partnering with HTC to make virtual reality headsets". Polygon. Retrieved March 1, 2015.
- Graser, Marc (March 1, 2015). "HTC, Valve to Launch Virtual Reality Headset Vive in 2015". Variety. Retrieved March 1, 2015.
- Suddath, Claire (April 25, 2012). "What Makes Valve Software the Best Office Ever?". Business Week.
- Suddath, Claire (April 27, 2012). "Why ThereAre No Bosses At Valve". Business Week.
- Petitte, Omri (February 13, 2013). "Valve lays off several employees in hardware, mobile teams [Updated]". PCGamer.com. PCGamer. Retrieved February 16, 2013.
- Varoufakis, Yanis (August 3, 2012). "Why Valve? Or, what do we need corporations for and how does Valve's management structure fit into today's corporate world?". Valve Economics. Retrieved August 12, 2012.
- Hern, Alex (August 3, 2012). "Valve Software: free marketeer's dream, or nightmare?". New Statesman.
- Warr, Philippa (July 9, 2013). "Former Valve Employee: 'It Felt a Lot Like High School'". Wired. Retrieved October 8, 2013.
- "Valve Time". Valve Corporation. Retrieved June 9, 2010.
- Kohler, Chris (June 9, 2010). "Valve Delays Portal 2 to 2011". Wired. Retrieved June 9, 2010.
- de Matos, Xav (November 18, 2010). "Portal 2 Delayed to 'The Week of April 18'". Shacknews. Retrieved November 18, 2010.
- Remo, Chris (February 24, 2010). "Valve's Faliszek: Team Self-Determination Drives Left 4 Dead 2 DLC Strategy". Gamasutra. Retrieved June 9, 2010.
- Yin-Poole, Wesley (July 12, 2012). "Valve on Valve Time: "It's charming. It's kind of a compliment."". Eurogamer. Retrieved July 12, 2012.
- Nutt, Christian (November 12, 2009). "Q&A: Valve's Swift On Left 4 Dead 2's Production, AI Boost". Gamasutra. Retrieved June 9, 2010.
- "Valve, Cisco, and a Host of PC Developers Unveil PowerPlay". IGN. January 7, 2000.
- "PowerPlay and interview". Planetfortress. 2000. Retrieved November 17, 2012.
- "Voodoo Extreme". Archived from the original on August 17, 2000. Retrieved November 17, 2012.
- "PowerPlay Preview". EuroGamer. January 19, 2000. Retrieved November 17, 2012.
Media related to Valve Software at Wikimedia Commons