Question:  PlayStation Underground was eventually merged with "Official U.S. PlayStation Magazine", a now-defunct monthly video game magazine, published by who?

Context paragraphs:
PlayStation Magazine Ufficiale: PlayStation Magazine Ufficiale, also known by the acronym "PSMU", initially named as "Ufficiale PlayStation Magazine" and after as "PlayStation 2 Magazine Ufficiale", is the Italian edition of "" video game magazine, specializing in all Sony video game consoles and handheld gaming platforms.  The magazine features previews, reviews, and cheat codes for Sony games.

PlayStation: The Official Magazine: PlayStation: The Official Magazine ("PTOM") was a magazine originally known as PlayStation Magazine (PSM), becoming "PlayStation: The Official Magazine" in late 2007.  "PlayStation: The Official Magazine" was published 13 times a year by Future plc until its cancellation in late 2012.

PlayStation Underground: PlayStation Underground is a now-defunct American video game magazine, originally published by Sony Computer Entertainment America.  The magazine focused on PlayStation fanbase, including gaming on the original Sony PlayStation and the PlayStation 2.  Unlike its paper-based counterpart the "Official U.S. PlayStation Magazine", PlayStation Underground came in the form of CD-ROMs which could be played on the PlayStation and PlayStation 2 consoles.  The magazine released its first issue on March 26, 1997 and ended with its final issue in 2001.  The Magazine released a total of seventeen issues during its active years.  The magazine was eventually merged with "Official U.S. PlayStation Magazine" in 2001 when it was discontinued.

Qore (PlayStation Network): Qore (pronounced like "core") was a monthly subscription-based interactive online magazine for the PlayStation Network and replaces the Jampack series of disks offered by PlayStation Underground.  Available only in North America, the service offered high definition videos, interviews, and behind-the-scenes footage pertaining to upcoming and recently released PlayStation games.  It also offered exclusive access to game demos and betas.  The product was available to download to the PlayStation 3 from the PlayStation Store, where users were able to choose to purchase individual episodes or an annual, 13-episode subscription.  PlayStation Plus subscribers received Qore free of charge for the duration of their subscription.  The magazine was presented by Veronica Belmont & Audrey Cleo and later Jesse 'Blaze' Snider & Tiffany Smith.

Official U.S. PlayStation Magazine: Official U.S. PlayStation Magazine (often abbreviated to OPM) is a now-defunct monthly video game magazine, published by Ziff Davis Media.  It was a sister publication of "Electronic Gaming Monthly".  The magazine focused exclusively on PlayStation hardware, software, and culture, covering the original PlayStation, PlayStation 2, PlayStation 3 and PlayStation Portable.  Perhaps the most famous aspect of the magazine was the inclusion each month of a disc that contained playable demos and videos of PlayStation games.  The magazine was produced for nearly ten years, from October 1997 to the final issue in January 2007.

Official Xbox Magazine: Official Xbox Magazine (or OXM for short) is a monthly video game magazine which started in November 2001 around the launch of the original Xbox.  A preview issue was released at E3 2001, with another preview issue in November 2001.  The magazine was bundled with a disc that included game demos, preview videos and trailers, and other content, such as game or Xbox updates and free gamerpics.  The discs also provided the software for the Xbox 360 for backward compatibility of original Xbox games for those without broadband and Xbox Live access.  As of January 2012, OXM no longer includes a demo disc.  In mid-2014, the U.S. version was merged into the UK version on the website, which lasted only a few months until Future plc announced that it was closing its website along with all the other websites that Future has published, including "Edge" and "Computer and Video Games".  In February 2015, "OXM" and all of Future's websites were redirected into GamesRadar.  The magazine itself continues to be published in the UK, US and Australia.

PlayStation Magazine (Italy): PlayStation Magazine, also known by the acronym PSM, is an Italian video game magazine specializing in all Sony video game consoles and handheld gaming platforms.  The magazine features previews, reviews, and cheat codes for Sony games.

Game Informer: Game Informer (GI) is an American monthly video game magazine featuring articles, news, strategy, and reviews of video games and associated consoles.  It debuted in August 1991 when FuncoLand started publishing a six-page magazine.  The publication is owned and published by GameStop Corp., the parent company of the video game retailer of the same name, who bought FuncoLand in 2000.  Due to this, a large amount of promotion is done in-store, which has contributed to the success of the magazine; it is now the 4th most popular magazine by copies circulated.  "Game Informer" has since become an important part of GameStop's customer loyalty program, Power Up Rewards, which offers subscribers access to special content on the official website.

Jampack: Jampack is a demo series from Sony under its PlayStation Underground brand.  It was used to advertise and preview upcoming, as well as already released PlayStation and PlayStation 2 games through demos and featurettes.  Often, it also included imported game demos, behind-the-scenes videos on developers and games, as well as cheat codes and saved games.  The Jampacks often served as a preview for the "PlayStation Underground" digital magazine and later online Ezine.

Irritating Stick: Irritating Stick, also known as Dengeki Iraira Bou Returns (電擊イライラ棒 リターンズ , lit.  "Irritating Electric Stick Returns" in Japanese) , is a PlayStation video game published by Jaleco Entertainment.  It is based on the Japanese game show "" (ウッチャンナンチャンの炎のチャレンジャーこれができたら100万円!!  , lit. " "Ucchan Nanchan's Challengers of Fire: 1,000,000 Yen If You Can Do This!!"")  .  The show in turn was based on a carnival game, where the player tries to maneuver a metal rod through a metal maze without touching the sides or else they would get shocked.  The player would also experience hearing a loud announcer screaming to confuse them while trying to escape the maze.  In the American Version of the game, the voices (except for when the maze is finished) were removed for unknown reasons.  "Irritating Stick" was originally released in Japan on March 19, 1998, and in North America on February 3, 1999.  There is also a demo of the Japanese version released in North America in 1998 on the "PlayStation Underground Jampack" in the "imports" section of the vault where it was spelled: "Ira-Ira Bo".  The player could only play up to level three, and some of the features were removed such as "multiplayer", "TV studio", "bonus", and "options".  Besides some of the removed content everything else such as the voice acting, narration, and intro movie were still there.  Japanese PlayStation games would not work on the American PlayStation console, so since this was a direct transfer of the game from the original disk, when a level is beaten or the player gets a "game over," the PlayStation console must be restarted.

Supporting paragraphs: PlayStation Underground Official U.S. PlayStation Magazine
Answer: Ziff Davis Media