Alexander Seropian (born 1969) is an American video game developer, one of the initial founders and later president of Bungie Software Products Corporation, the developer of the "Marathon", "Myth", and "Halo" video game series.
 Seropian became interested in computer programming in college and teamed up with fellow student Jason Jones to publish Jones's game "".
 The two became partners, and Bungie grew to become the best-known Apple Macintosh game developer before being bought by Microsoft in 2001.
American Game Cartridges (AGC) was an American video game developer and publisher established as a subsidiary of ShareData in 1990.
 Like ShareData, American Game Cartridges was headquartered in Chandler, Arizona.
 AGC published three video games for the Nintendo Entertainment System (NES) in 1990.
Activision Blizzard, Inc. is an American video game developer.
 Headquartered in Santa Monica, California and founded in 2008 through the merger of Vivendi Games and Activision, the company is traded on the NASDAQ stock exchange under the ticker symbol NASDAQ: ATVI , and since 2015 has been one of the stocks that make up the S&P 500.
 Activision Blizzard currently includes five business units: Activision, Blizzard Entertainment, Major League Gaming, Activision Blizzard Studios, and King Digital Entertainment.
Tim Rogers (born June 7, 1979) is an American video game journalist and developer.
 In games journalism, he is known for his association with mid-2000s New Games Journalism, his verbose writing style, and his video game reviews website "ActionButton.net".
 "The Guardian" cited his 2005 "Dreaming in an empty room: a defense of "Metal Gear Solid 2"" as a core example of New Games Journalism, a style of video game journalism that emphasizes the author's subjective and personal experiences in relation to the game world.
 Rogers has also written for "Next Generation", "GamesTM", "Play", "Game Developer", and "Kotaku".
Crystal Dynamics is an American video game developer that was founded in 1992 by Judy Lang, Madaline Canepa and Dave Morris.
 Based in the San Francisco Bay Area, California, Crystal Dynamics was the first licensed developer for Panasonic's original 3DO console, a gaming hardware platform founded by Kleiner Perkins.
 Their first release, "Crash N Burn", was a launch game for the system and was included as a pack-in game with the console.
 The 3DO's launch during the 1993 Christmas season was a commercial failure, severely damaging Crystal Dynamics' software strategy.
 In 1994, the company became a publisher for two new gaming platforms, the PlayStation and the Sega Saturn.
 The studio was acquired by Eidos Interactive, a British video game publisher, in 1998.
 After Square Enix acquired Eidos in 2009, Crystal Dynamics became a subsidiary of Square Enix.
Demonware is an Irish software development company and a subsidiary of Activision Blizzard.
 Demonware's products enable games publishers to outsource their networking requirements, allowing them to concentrate on playability.
 The organisation has offices in Dublin, Ireland; Vancouver, Canada; and Shanghai, China;.
Atari, Inc. was an American video game developer and home computer company founded in 1972 by Nolan Bushnell and Ted Dabney.
 Primarily responsible for the formation of the video arcade and modern video game industries, the company was closed and its assets split in 1984 as a direct result of the North American video game crash of 1983.
Bungie, Inc. or Bungie Inc., sometimes referred to as Bungie, Incorporation or Bungie Incorporation, Bungie, Incorporated or Bungie Incorporated, also known as Bungie Studios, commonly known as Bungie, LLC or Bungie LLC, or simply Bungie, formerly Bungie Software Products Corporation, more popularly called "Bungie Software" prior to its emancipation from Microsoft, is an American video game developer located in Bellevue, Washington, United States.
 The company was established in June 1991 as "Bungie Software Products Corporation", more popularly called "Bungie Software" by University of Chicago undergraduate student Alex Seropian, who later brought in programmer Jason Jones after publishing Jones' game "".
 Originally based in Chicago, Illinois, the company concentrated primarily on Macintosh games during its early years and created two very successful video game franchises called "Marathon" and "Myth".
 A West Coast offshoot produced the PC and console title "Oni" (now owned by Rockstar Games, a publishing subsidiary of Take-Two Interactive which at the time owned 20% of the developer).
Crystal Dynamics, Inc. is an American video game developer that was founded in 1992 by Judy Lang, Madeline Canepa and Dave Morse.
 Based in the San Francisco Bay Area, it was acquired by Eidos Interactive in 1998.
 After Square Enix's acquisition of Eidos in 2009, it became a subsidiary of Square Enix.
 Crystal Dynamics was the first licensed developer for 3DO.
 The company's mascot was the video game character Gex the Gecko.
En Masse Entertainment, Inc. (formerly Bluehole Interactive, Inc.) is an American video game publisher and a subsidiary of South Korean video game developer Bluehole.
 Founded in June 2008, the company is based in Seattle, Washington and is best-known for publishing massively multiplayer online role-playing game "TERA", which was developed by parent company Bluehole.
 The original En Masse leadership team had extensive experience in the video game industry at leading companies, including Blizzard Entertainment, Microsoft, NCsoft, ArenaNet, and Electronic Arts.
 In January 2013, Chris Lee and Soo Min Park became chief executive officer and chief operating officer, respectively.

Question: Where was the American video game developer which has Demonware as a subsidiary headquartered? 
Answer: Santa Monica, California