Question: Which company founded by ex-Black Isle employees developed the game Neverwinter Nights?

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Neverwinter Nights 2: Storm of Zehir: Neverwinter Nights 2: Storm of Zehir is an expansion pack for the role-playing video game "Neverwinter Nights 2", developed by Obsidian Entertainment and published by Atari.  It was released in late 2008 in North America, Europe, and Australia.  Like previous entries in the "Neverwinter Nights" series, "Storm of Zehir" is based on the paper and pencil fantasy role-playing game "Dungeons & Dragons", and uses the game's 3.5 edition ruleset.

Alan Miranda: Alan Miranda is a previous BioWare employee, who had worked on "Dungeons & Dragons" titles like "Neverwinter Nights" and "".  In 2003, he left BioWare to form his own company, Ossian Studios, with his wife Elizabeth Starr.  Miranda approached BioWare joint CEO Greg Zeschuk in 2005 to discuss the possibility of Ossian developing a "premium module" for "Neverwinter Nights".  Premium modules were adventures created for "Neverwinter Nights" by BioWare and other companies.  BioWare had been given autonomy on the premium module process from the game's publisher, Atari, and Zeschuk approved Miranda's proposal.  Miranda's initial draft of the project was a pirate-themed adventure in the Sword Coast, which happened to be the same idea that BioWare itself was creating a premium module for, "".  Miranda revised the concept and chose the Western Heartlands as the setting.  Ossian estimated that a module on par with other large games like "Kingmaker" would take four to five months.  Pre-production on "Darkness over Daggerford" began in April 2005 and took a month and a half.  Ossian went through five designers in this stage, none of whom worked out.  Choosing a designer required much of the time allocated for pre-production, and to compensate Ossian developers immediately began creating the game, fleshing out details as they went.  In May 2006, Atari cancelled the premium module program, with no warning to developers of the current projects.  Miranda and his team decided to finish the game anyway, and in August 2006 it was released free of charge on IGN's Neverwinter Nights Vault.

Obsidian Entertainment: Obsidian Entertainment, Inc. is an independent American video game developer whose corporate headquarters are located in Irvine, California.  It was founded in 2003 shortly before the closure of Black Isle Studios by ex-Black Isle employees Feargus Urquhart, Chris Avellone, Chris Parker, Darren Monahan, and Chris Jones.

Neverwinter Nights 2: Mysteries of Westgate: Neverwinter Nights 2: Mysteries of Westgate (NWN2:MoW) is an expansion pack for the role-playing video game "Neverwinter Nights 2".  It was developed by Ossian Studios and published by Atari on April 29, 2009.  The player creates a character and controls it, along with a group of three pre-designed companions, journeying through the game world.  The gameplay is very similar to that of the base game.  "Mysteries of Westgate" also includes new monsters, music, and other tools, which can be used by players to create their own "Neverwinter Nights 2" levels.

The Known Lands: The Known Lands (TKL) is a 'home grown' world in the "Neverwinter Nights 2" role-playing environment that has been developed around the persistent world structure.  The self-stated goal of this project is to make a world that is roleplay focused with the feel of a ‘pen and paper’ (PnP) game.  In order to get that PnP feel, it includes a feature similar to traditional PnP – the use of adventuring parties in the world, with human dungeon masters.  The world is based on the "Neverwinter Nights 2" client and has been active since October 2006.

Neverwinter Nights 2: Neverwinter Nights 2 is a role-playing video game developed by Obsidian Entertainment and published by Atari, Inc. It is the sequel to BioWare's "Neverwinter Nights", based on the "Dungeons & Dragons" pencil and paper fantasy role-playing game.  "Neverwinter Nights 2" utilizes an adaptation of the "Dungeons & Dragons" 3.5 edition rules.  Players create player characters to represent themselves in the game, using the same character creation rules as found in the "Dungeons & Dragons" game.  They may gain the assistance of additional party members, and they eventually acquire a keep that can be used as a base of operations.  "Neverwinter Nights 2" is set in the Forgotten Realms campaign setting—in and around the city of Neverwinter.  The story is mostly unrelated to "Neverwinter Nights" and follows the journey of an orphaned adventurer investigating a group of mysterious artifacts known as "silver shards" and their connection to an ancient, evil spirit known as the King of Shadows.

Neverwinter Nights (series): Neverwinter Nights is a series of video games developed by BioWare and Obsidian Entertainment, based on the "Forgotten Realms" campaign setting of the "Dungeons & Dragons" role-playing game.  It is unrelated to the 1991 online game of the same name distributed by AOL.

Neverwinter (video game): Neverwinter is a free-to-play massively multiplayer online role-playing game developed by Cryptic Studios and released by Perfect World Entertainment for Microsoft Windows in 2013, Xbox One in 2015, and PlayStation 4 in 2016.  Based in the fictional Forgotten Realms city of Neverwinter from "Dungeons & Dragons", "Neverwinter" is a standalone game and not part of the previous "Neverwinter Nights" series.

Neverwinter Nights 2: Mask of the Betrayer: Neverwinter Nights 2: Mask of the Betrayer is a role-playing video game developed by Obsidian Entertainment and published by Atari.  It is an expansion pack for "Neverwinter Nights 2".  It was released in Autumn 2007 for the PC in North America, Europe, and Australia.  Like the first game, "Mask of the Betrayer" is set in the Forgotten Realms campaign setting of the paper and pencil role-playing game "Dungeons & Dragons" and employs the 3.5 edition rules.

Savage Frontier (series): The Savage Frontier is a region in the Dungeons & Dragons campaign setting the Forgotten Realms.  The Savage Frontier video game series, developed by Stormfront Studios and published by Strategic Simulations, Inc., is the series that precedes the "Neverwinter Nights" series, with the introduction of the city of Neverwinter in its games.  The first game in the series was "Gateway to the Savage Frontier".  It was followed by two sequels after this, "Treasures of the Savage Frontier" and Neverwinter Nights

Supporting paragraphs: Neverwinter Nights (series) Obsidian Entertainment
Answer: Obsidian Entertainment