|Subsidiary of Activision Blizzard|
|Founded||1979 (as On-Line Systems)
2014 (as subsidiary of Activision Blizzard)
|Headquarters||Fresno, California, U.S.|
|Martin Tremblay (President)
Al Simone (Senior Vice President of Global Marketing)
|Products||Metal Arms: Glitch in the System
King's Quest series
Space Quest series
Leisure Suit Larry series
The Adventures of Willy Beamish
Gabriel Knight series
Quest for Glory series
Police Quest and SWAT series
The Incredible Machine series
Lighthouse: The Dark Being
Sierra Entertainment, Inc. is an American video-game developer and publisher founded in 1979 as On-Line Systems by Ken and Roberta Williams. Based in Oakhurst, California and later in Fresno, California, the company is owned by Activision, a subsidiary of Activision Blizzard.
Sierra is best known today for its multiple lines of seminal graphic adventure games started in the 1980s, many of which proved influential in the history of video games. The Sierra label was absorbed by its parent company in 2008. Some franchises (such as Crash Bandicoot and Spyro the Dragon) that were published by Sierra will be published by Activision. On August 7, 2014, Sierra's website was re-activated, with a new logo and a message saying "More to be revealed at Gamescom 2014."
- 1 History
- 1.1 Founding
- 1.2 1980s
- 1.2.1 The Hi-Res Adventure series
- 184.108.40.206 Hi-Res Adventure 0 – Mission Asteroid
- 220.127.116.11 Hi-Res Adventure 1 – Mystery House
- 18.104.22.168 Hi-Res Adventure 2 – Wizard and the Princess
- 22.214.171.124 Hi-Res Adventure 3 – Cranston Manor
- 126.96.36.199 Hi-Res Adventure 4 – Ulysses and the Golden Fleece
- 188.8.131.52 Hi-Res Adventure 5 – Time Zone
- 184.108.40.206 Hi-Res Adventure 6 – The Dark Crystal
- 220.127.116.11 B.C's Quest for Tires series
- 18.104.22.168 Disney collaborations
- 1.2.2 Other games
- 1.2.1 The Hi-Res Adventure series
- 1.3 1990s
- 1.3.1 Dr. Brain series
- 1.3.2 Freddy Pharkas: Frontier Pharmacist
- 1.3.3 Gabriel Knight series
- 1.3.4 Lode Runner: The Legend Returns
- 1.3.5 Outpost Series
- 1.3.6 Move to Bellevue, Washington
- 1.3.7 Phantasmagoria
- 1.3.8 3D Ultra Lionel Traintown
- 1.3.9 Sold to CUC
- 1.3.10 Cendant Corporation
- 1.3.11 The Cendant scandal
- 1.3.12 Major layoffs
- 1.4 Yosemite Entertainment legacy
- 1.5 2000s
- 1.6 2010s
- 2 Management teams
- 3 Studios
- 4 See also
- 5 References
- 6 External links
Sierra Entertainment was founded in 1979 as On-Line Systems in Simi Valley, California, by Ken and Roberta Williams. Ken Williams, a programmer for IBM, bought an Apple II microcomputer which he planned to use to develop a Fortran compiler for the Apple II. At the time, his wife Roberta Williams was playing text adventure games on the Apple II. Dissatisfied with the text-only format, she realized that the graphics display capability of the Apple II could enhance the adventure gaming experience. After initial success, On-Line Systems was renamed Sierra On-Line in 1982, and the company moved to Oakhurst, California. By early 1984 InfoWorld estimated that Sierra was the world's 12th-largest microcomputer-software company, with $12.5 million in 1983 sales.
The Hi-Res Adventure series
Hi-Res Adventure 0 – Mission Asteroid
Hi-Res Adventure 1 – Mystery House
Roberta began to write a script for an adventure game. Three weeks later, she presented to Ken the script of a video game called Mystery House, an idea she had developed during the previous days. Roberta managed to talk Ken into helping her develop the game in the evenings after work. She worked on the text and the graphics, and told Ken how to put it all together to make it the game she wanted. They worked on it for about three months and, on May 5, 1980, Mystery House was ready for shipment. Mystery House was an instant hit. It was the first computer adventure game to have graphics, although they were crude, monochrome, static line drawings. It sold about 15,000 copies and earned $167,000.
Hi-Res Adventure 2 – Wizard and the Princess
Wizard and the Princess, also known as Adventure in Serenia, is a 1980 video game by On-Line Systems for the Apple II and Apple II Plus. It is the second title released in On-Line Systems' "Hi-Res Adventure" series after Mystery House. It is a prelude to the King's Quest series in both story and concept.
Hi-Res Adventure 3 – Cranston Manor
Cranston Manor is a graphic adventure game released in 1981. It was created by Ken Williams and Harold DeWitz. In the game, the player must invade a mansion that was occupied by a millionaire and steal the sixteen treasures that are inside of it. The game allows players to switch between graphics-based and text-based gameplay.
Hi-Res Adventure 4 – Ulysses and the Golden Fleece
Hi-Res Adventure 5 – Time Zone
A multi-disk graphical adventure game written and directed by Roberta Williams for the Apple II. Developed in 1981 and released in 1982 by On-Line Systems, the game was shipped with six double sided floppy disks and contained 1,500 areas (screens) to explore along with 39 scenarios to solve. Produced at a time when most games rarely took up more than one side of a floppy, Time Zone is believed to be one of if not the very first game of this magnitude ever released for home computer systems.
Since half the locations were red herrings, strategy included finding what areas were to be avoided as time- and effort-consuming diversions.
Hi-Res Adventure 6 – The Dark Crystal
A graphic adventure game based on Jim Henson's fantasy film, The Dark Crystal. The game was designed by Roberta Williams and published under the SierraVenture line in 1983 as Hi-Res Adventure #6: The Dark Crystal. It was the first Hi-Res Adventure released under the SierraVenture line, the previous titles being released under earlier names and later re-released under SierraVenture. Development took a little over a month. A simplified version written by Al Lowe, titled Gelfling Adventure, was released in 1984 and was intended for a younger audience.
B.C's Quest for Tires series
One of the earliest side-scrolling "forced runner" games.
Sierra On-line published several titles in collaboration with The Walt Disney Company.
- Donald Duck's Playground (1984)
- Mickey's Space Adventure (1984)
- Winnie the Pooh in the Hundred Acre Wood (1986)
- The Black Cauldron (1986)
The King's Quest series
Sierra On-Line was contacted by IBM in 1983 to create a game for its new PCjr. IBM would fund the entire development of the game, pay royalties for it, and advertise for the game. Ken and Roberta accepted and started on the project.
Roberta created a story featuring classic fairy-tale elements. Her game concept included animated color graphics, a pseudo 3D-perspective where the main character was visible on the screen, a more competent text parser that would understand advanced commands from the player, and music playing in the background through the PCjr sound hardware. For the game, a complete development system called Adventure Game Interpreter was developed.
In the summer of 1984, King's Quest was released to much acclaim.
The Space Quest series
While working to finish The Black Cauldron, programmers Mark Crowe and Scott Murphy began to plan for an adventure game of their own. After a simple demonstration to Ken, he allowed them to start working on the full game, which was named Space Quest: The Sarien Encounter. The game, released in October 1986, was an instant success and would spawn many sequels in the following years.
The Leisure Suit Larry series
Al Lowe, who had been working at Sierra On-Line for many years, was asked by Ken Williams to write a modern version of Chuck Benton's Softporn Adventure from 1981, the only pure text adventure that the company had ever released.
Leisure Suit Larry in the Land of the Lounge Lizards was a great hit (although it first became famous as an early example of software piracy, as Sierra sold many more hintbooks than actual copies of the game) and won the Software Publishers Association's Best Adventure Game award of 1987. A long series of Leisure Suit Larry games would follow in the coming years and become the second best selling game series of Sierra On-Line after King's Quest.
The Police Quest and SWAT series
Ken Williams befriended a retired highway patrol officer named Jim Walls, and asked him to produce an adventure series based on a police theme. Walls proceeded to create Police Quest: In Pursuit of the Death Angel, and two sequels. The series was touted for its adherence to police protocol (relevant parts of which were explained in the games' manuals), and presenting some real-life situations encountered by Walls during his career as an officer.
After Walls left Sierra in the late 1990s, Los Angeles Chief of Police Daryl F. Gates was brought in to take control of the series, producing a fourth adventure game before reorienting the series into the First Person Shooter genre.
The Quest for Glory series
Quest for Glory is a series of hybrid adventure/role-playing video games (and later Action/RPG for game 5) designed by Corey and Lori Ann Cole. The series combined humor, puzzle elements, themes and characters borrowed from various legends, puns, and memorable characters, creating a 5-part series of the Sierra stable.
Although the series was originally titled Hero's Quest, Sierra failed to trademark the name. Milton Bradley successfully trademarked an electronic version of their unrelated joint Games Workshop board game, HeroQuest, which forced Sierra to change the series' title to Quest for Glory. This decision caused all future games in the series (as well as newer releases of Hero's Quest I) to switch over to the new name.
In 1990, Sierra released King's Quest V. It would be the first Sierra On-Line game ever to sell more than 500,000 copies and was the highest selling game for the next five years. It won several awards as well, such as the Best Adventure Game of the Year from both the Software Publishers Association and Computer Gaming World Magazine.
The Sierra Network provided a "land based" precursor to MMPRPGs and internet chat rooms. Each land themed for the type of content provided multi-player gaming and category based bulletin boards and chat rooms throughout the continental United States.
Dr. Brain series
The original two games, Castle of Dr. Brain (1991) and The Island of Dr. Brain (1992), are hybrid puzzle adventure games considered to be the start of a series of education games created by an in-house team at Sierra.
Freddy Pharkas: Frontier Pharmacist
The last original game to use SCI 1.1 was Freddy Pharkas: Frontier Pharmacist, a game written by Josh Mandel and Al Lowe, released in 1993. According to Lowe, it was meant as a take on Blazing Saddles, a tongue-in-cheek Western. The game did not spawn any sequels.
Gabriel Knight series
In 1993, Gabriel Knight: Sins of the Fathers was released. Generally considered to be a staple of the point-and-click adventure genre, the game and its sequels were critically acclaimed in the mainstream press at the time.
Lode Runner: The Legend Returns
In 1994, Lode Runner: The Legend Returns was released. The game won many awards, including the 1994 Game of the Year award from Games Magazine in the "Best New Arcade Game" category.
In 1994 and 1997 Outpost and Outpost 2: Divided Destiny was released. 
Move to Bellevue, Washington
Sierra had grown enormously since its first years, and a new building would be needed to expand its operations to continue making games. A decision was made to move the headquarters north to Bellevue, Washington. Sierra's original location in Oakhurst continued as an internal development studio for the company and was renamed Yosemite Entertainment in 1998.
The company was now made up of five separate and largely autonomous development divisions: Sierra Publishing, Sierra Northwest, Dynamix, Bright Star Technology, and Coktel Vision, with each group working separately on product development but sharing manufacturing, distribution, and sales resources.
The year 1995 would prove to be an extremely successful year for the company. With $83.4 million in sales from its software-publishing business, earnings were improved by 19 percent, bringing a net income of $11.9 million to the company.
In June 1995, Sierra and Pioneer Electric Corp. signed an agreement to create a joint venture that would develop, publish, manufacture, and market entertainment software for the Japanese software market. This joint venture created a new company called Sierra Venture. With Sierra and Pioneer investing over $12 million, the new company immediately manufactured and shipped over twenty of Sierra's most popular products to Japan and created new titles for the Japanese market.
December 1996 saw the release of The Realm Online, a massively multiplayer online game. At its peak, it had over 25,000 players. Ken Williams acted as Executive Producer of the Realm from its release until late 1998.
Phantasmagoria was by far the largest project ever undertaken by Sierra. At the time of its release in late 1995, the anticipation for the game was incredibly high. Although nearly one million copies were sold when the game was first released in August 1995, making it the best-selling Sierra adventure game created, the game received mixed reviews from industry critics.
3D Ultra Lionel Traintown
In 1999, Sierra Entertainment released 3D Ultra Lionel Traintown.
Sold to CUC
In 1996, CUC International, a membership-based consumer services conglomerate, aggressively sought to expand into interactive entertainment and, in February 1996, offered to buy Sierra at a price of approximately $1.5 billion. The deal with CUC closed on July 24, 1996. Immediately after the sale, Ken Williams stepped down as CEO of Sierra. He stayed with the software division as a Vice President of CUC so that he could provide strategic guidance to Sierra and began to work on CUC's online product distributor, NetMarket. One year later, Ken and Roberta left CUC.
In September 1996, CUC announced plans to consolidate some of the functions of its game companies into a single company called CUC Software Inc., headquartered in Torrance, California. Davidson & Associates became the publisher for the studio. CUC Software would consolidate the manufacturing, distribution, and sales resources of all of its divisions that would come to include Sierra, Davidson, Blizzard, Knowledge Adventure, and Gryphon Software.
On November 5, 1996, Sierra was restructured into three units.
In December 1997, CUC merged with HFS Incorporated. The two companies jointly formed the Cendant Corporation with more than 40,000 employees and operations in over 100 countries.
In 1998, Sierra split up its organization into 4 sub-brands and corporate divisions:
- Sierra Attractions (For casual games such as poker)
- Sierra Home (For home/lifestyle software)
- Sierra Sports (For sports games)
- Sierra Studios (General publishing division)
The Cendant scandal
In March 1998, Cendant had reported a 1997 net income of $55.4 million. However, the true 1997 result was a net loss of $217.2 million. As irregularities in the books of Cendant were discovered in early 1998, an audit committee set up by Cendant's Board of Directors launched an investigation and discovered that the former management team of CUC, including its top executives Walter Forbes and Kirk Shelton, had been fraudulently preparing false business statements for several years.
In March 2001, Forbes and Shelton were indicted by a federal grand jury and sued by the Securities and Exchange Commission, which accused the company of directing the massive accounting fraud that ultimately cost the company and its investors billions of dollars. With the news of the accounting fraud, Cendant announced its intention to sell off its entire computer entertainment division.
On November 20, 1998, Cendant announced the sale of its entire consumer software division to Paris-based Havas S.A. With this sale, Sierra became a part of Havas Interactive, the interactive entertainment division of the company.
On February 22, 1999, Sierra announced a major reorganization of the company, resulting in the shutdown of several of their development studios, cutbacks on others and the relocation of key projects, and employees from those studios, to Bellevue. About 250 people in total lost their jobs. Development groups within Sierra such as PyroTechnix were shut down. Others such as Books That Work were relocated to Bellevue. Also shut down was Yosemite Entertainment, the division occupying the original headquarters of Sierra On-Line. The company sold the rights of Headgate Studios back to the original owner. With the exception of the warehouse and distribution department, the entire studio was shut down. Game designers Al Lowe and Scott Murphy were laid off. Lowe had just started work on Leisure Suit Larry 8. Murphy was involved in a Space Quest 7 project at the time. Layoffs continued on March 1, when Sierra terminated 30 employees at the previously unaffected Dynamix, 15 percent of its workforce.
Despite the layoffs, Sierra continued to publish games for smaller development houses. In September 1999, they released Homeworld, a real-time space-combat strategy game developed by Relic Entertainment. The game design was revolutionary for the genre, and the game received great critical acclaim and many awards.
Gabriel Knight 3 was released on November 3, 1999. It was announced this would be the last game of the series.
Yosemite Entertainment legacy
UK-based games developer and publisher Codemasters, in an effort to establish themselves in the United States, announced that it would launch a new development studio in Oakhurst, using the abandoned Sierra facilities and hiring much of the Yosemite Entertainment's laid-off staff in mid-September 1999. In early October the company announced that it would take over management and maintenance of the online RPG The Realm and that it would pick up and complete the previously canceled Navy SEALs. The company also reported that it had obtained the rights to continue using the name Yosemite Entertainment for the development house.
Meanwhile, Sierra announced another reorganization, this time into three business units: Core Games, Casual Entertainment, and Home Productivity. This reorganization resulted in even more layoffs, eliminating 105 additional jobs and a number of games in production. After 1999, Sierra almost entirely ceased to be a developer of games and, as time went on, instead became a publisher of games by independent developers.
- Coktel Vision
- The Pixellite Group
- Green Thumb Software
- Arion Software
- Impressions Games
- Papyrus Design Group
- Synergistic Software
- Headgate Studios
- Berkeley Systems
- Books That Work
At the end of June 2000, a strategic business alliance between Vivendi, Seagram, and Canal+ was announced, and Vivendi Universal, a leading global media and communications company, was formed after the merger with Seagram (the parent company of Universal Studios). Havas S.A. was renamed Vivendi Universal Publishing and became the publishing division of the new group, divided into five groups: games, education, literature, health, and information. The merger was followed by many more layoffs of Sierra employees.
On February 19, 2002, Sierra On-Line officially announced the change of its name to Sierra Entertainment, Inc.
In 2002, Sierra, working with High Voltage Software, announced the development of a new chapter in the Leisure Suit Larry franchise, titled Leisure Suit Larry: Magna Cum Laude. It was released to mostly negative reviews; Larry's creator, Al Lowe, was not involved with the project.
The newly renamed Sierra Entertainment continued to develop mostly unsuccessful interactive entertainment products. However, its hit Homeworld 2 once again cemented Sierra's reputation as a respectable publisher.
In 2003, Sierra Entertainment released the second videogame adaptation of The Hobbit.
Cost-cutting measures were taken because of parent company Vivendi Universal Games' (VU Games') financial troubles and because of Sierra's lack of profitability as a working developer. Impressions Games and the Papyrus Design Group were shut down in the spring of 2004, and about 50 people lost their jobs in those cuts; 180 Sierra-related positions were eliminated at Vivendi's Los Angeles offices; and finally in June 2004, VU Games shut down Sierra's Bellevue location, which cost over 100 people their jobs, dispersed Sierra's work to other VU Games divisions, and relocated the company to Vivendi Universal Games's corporate headquarters in Fresno, California. Other titles, such as Print Artist, were permanently discontinued. The Hoyle franchise was sold to an independent developer. In total, 350 people lost their jobs.
In late 2005, the Sierra brand was re-launched from Los Angeles, including the Sierra Online brand, which was to focus on online-only titles.
Several studios including Massive Entertainment, High Moon Studios, Radical Entertainment, Secret Lair Studios / Studio Ch'in (based in Seattle and Shanghai) and Swordfish Studios were acquired and integrated into Sierra throughout 2005 and 2006. Creative licenses from other Vivendi divisions and from companies partnered with Vivendi Universal Games were granted to Sierra, and copyright of several notable intellectual properties, such as Crash Bandicoot, Spyro the Dragon, 50 Cent: Bulletproof and Scarface, went to Sierra.
In the summer of 2007, Sierra Online began launching Xbox Live Arcade titles for the Xbox 360. One of its first releases was the conversion of the successful "German-style" board game Carcassonne, which had been in development at Secret Lair Studios.
In October 2007, Sierra released Timeshift.
In 2008, Sierra parent company Vivendi Universal Games, which had since been renamed Vivendi Games in 2006, merged with video game publisher Activision to form the Activision Blizzard holding company. Vivendi Games ceased to exist and ownership of Sierra was transferred over to Activision. Later that year, Sierra was closed down for possible future sale.
On August 7, 2014, the website for Sierra, which previously redirected to Activision's website, was updated, showcasing a new logo, teasing that "More to be revealed at Gamescom 2014.". The revived Sierra Entertainment will re-release some of their older games, re-imaging their older franchise, as well as collaborate with indie studios to create new "innovative, edgy and graphically unique" projects. According to a statement from the company, Sierra will focus on publishing downloadable games through PlayStation Network, Steam for PC and Xbox Live. "We're very proud of what we created all those years ago with Sierra Online, and today's news about carrying Sierra forward as an indie-specific brand is very encouraging," said Sierra founder Ken Williams in an official statement. "We look forward to seeing Sierra's independent spirit live on." On the same day, King's Quest and Geometry Wars 3: Dimensions was announced and will be the first 2 games publishing under the Sierra brand.
Ken Williams (company co-founder):
- CEO (1979 – November 1997)
- President (1979–1981;1983–1995)
- Chairman (September 1988 – July 1996)
- President (1981 – Summer 1983)
- CFO and Senior Vice President (June 1994 – October 1995)
- President and COO (October 1995 – October 1997)
- President (June 1998 – June 2001)
Thomas K. Hernquist
- President (June 2001)
- COO and Vice President of Product Development (June 2001)
- President (June 2001 – June 2004)
- Books That Work
- Bright Star Technology in Bellevue, Washington, founded 1980, acquired 1992.
- Green Thumb Software, acquired in 1995.
- Berkeley Systems in Berkeley, California, founded in 1987, acquired in 1997, closed 2000.
- Dynamix in Eugene, Oregon, founded 1984, acquired August 1990, closed August 14, 2001.
- Front Page Sports, closed Jan 28, 1998.
- Impressions Games in Cambridge, Massachusetts, founded 1989, acquired 1995, closed April 2004.
- Papyrus Design Group in Watertown, Massachusetts, founded in 1987, acquired 1995, closed May 2004.
- PyroTechnix, founded as Computer Presentation, acquired February 1996, closed in 1999.
- Yosemite Entertainment in Oakhurst, California, formed in 1998, closed in 1999 then sold to Codemasters that year.
- As of late 2008–2009, Sierra Co. was shut down.
Merged with Activision
- High Moon Studios in San Diego, California, founded in 2001, acquired by Vivendi Games in January 2006.
- Radical Entertainment in Vancouver, Canada, founded in 1991, acquired by Vivendi Games in 2005.
- Coktel Vision in Paris, France, founded in 1985, acquired in 1993, sold to Mindscape in 2005.
- Headgate Studios in Bountiful, Utah, founded in 1992, acquired April 1996, sold to original owner in 1999.
- Massive Entertainment in Malmö, Sweden, founded in 1987, acquired by Vivendi Games in 2002, sold to Ubisoft on November 10, 2008.
- Swordfish Studios in Birmingham, England, founded in September 2002, acquired by Vivendi Games in June 2005, sold to Codemasters on November 14, 2008.
- Synergistic Studios, founded in 1978, acquired in 1996, studio closed in 1999. No longer involved in the video game industry.
Sierra Home titles
- Generations 1–8 – A family tree program for Windows 95–98 worked on Windows after that, but with many bugs.
- Power Chess – a game that teaches how to play chess
- Hoyle Card Games – a collection of popular card games such as Poker, Bridge, Euchre, Hearts, Spades
- Hoyle Board Games – a collection of popular board games
- Hoyle Puzzle Games
- Hallmark Card Studio – publishing rights later given to Nova
- AGD Interactive
- Activision Blizzard
- Infamous Adventures
- The Silver Lining (game)
- List of Sierra Entertainment video games
- Vivendi Games
- "Sierra Legal Information". Sierra Entertainment. Archived from the original on 2007-02-02. Retrieved 2008-07-30.
- "Sierra Entertainment set to return with new game at Gamescom 2014". Shacknews. August 7, 2014. Retrieved August 7, 2014.
- Levy, Stephen (1984). Hackers: Heroes of the Computer Revolution. Doubleday. ISBN 0-385-19195-2.
- Caruso, Denise (1984-04-02). "Company Strategies Boomerang". InfoWorld. pp. 80–83. Retrieved 10 February 2015.
- Interaction Magazine, Fall 1994
- Cranston Manor at MobyGames
- "Hi-Res Adventure #4: Ulysses and the Golden Fleece". Moby Games.
- "Time Zone: An interview with Roberta Williams". Computer Gaming World. May–June 1982. pp. 14–15.
- "The dark crystal.". www.atarimagazines.com. Retrieved 2008-09-13.
- "Inside the Industry". Computer Gaming World. June 1991. p. 62. Retrieved 17 November 2013.
- Metacritic: Phantasmagoria (pc: 1995)
- "Headgate Studios: About". Headgate Studios. Archived from the original on 2007-09-15. Retrieved 2009-08-25.
- Alexa Ray Corriea (August 12, 2014). "Geometry Wars and King's Quest return with revived Sierra label". Polygon. Retrieved August 12, 2014.
- Chris Pereira (August 17, 2014). "Geometry Wars 3, New King's Quest From Sierra Announced at Gamescom 2014". GameSpot. Retrieved August 17, 2014.
- Patrick Klepek (August 17, 2014). "Sierra's Coming Back With King's Quest, Geometry Wars". Giant Bomb. Retrieved August 17, 2014.
- Martin Robinson (August 17, 2014). "Sierra is back – and so are Geometry Wars and King's Quest". Eurogamer. Retrieved August 17, 2014.
- Hamza Aziz (August 17, 2014). "Sierra is back! New King's Quest and, uh, Geometry Wars coming". Destructoid. Retrieved August 17, 2014.
- Kevin Dunsmore (December 5, 2014). "The Game Awards 2014 Full List Of Winners Revealed". Hardcore Gamer. Retrieved December 5, 2014.
- "History for Sierra Entertainment, Inc.". MobyGames. Retrieved 2009-08-25.
- "Codemasters Software Co Ltd acquires Yosemite Entertainment from Vivendi SA". The Alcra Store. September 21, 1999. Retrieved 2009-08-25.
- Interview with Ken Williams, Gamasutra, October 2005
- An Interview With Russisk Laawson, Module And Graphics Designer: 2006-10-12
- HACKERS, Heroes of the Computer revolution, Steven Levy, reprinted – Penguin Books 1994, ISBN 0-14-023269-9
- Official website
- SCIprogramming.com – Community using Sierra's AGI and SCI technology to create adventure games
- SierraGamers – Official Website of the Founders of Sierra