Question: MxO was billed as an official continuation of the storyline of a franshise created by film directors formerly known as what?

<P0-S0> Monticello Regional Airport (IATA: MXO, ICAO: KMXO, FAA LID: MXO) , formerly known as Monticello Municipal Airport, is a public airport located two miles (3 km) southeast of the central business district of Monticello, a city in Jones County, Iowa, United States. <P0-S1>  It is owned by the City of Monticello. <SEP> <P1-S0> The Directors Guild of Japan (日本映画監督協会 , Nihon Eiga Kantoku Kyōkai ) is a trade union created to represent the interests of film directors in the film industry in Japan. <P1-S1>  It was founded in 1936, with Minoru Murata serving as the first president, and has continued to this day apart from a period between 1943 and 1949 when it was disbanded at first on orders from the government. <P1-S2>  It is particularly concerned with protecting the copyright and other rights the director has over the work, defending freedom of expression, and promoting the economic interests of its members. <P1-S3>  For instance, it has issued protests against efforts to prevent screenings of such films as "Yasukuni" and "The Cove". <P1-S4>  The Guild also produced the film "Eiga kantoku tte nan da" ("What Is a Film Director?") <P1-S5>  on the occasion of its 70th anniversary to promote its view that the director possesses the copyright of a film. <SEP> <P2-S0> The Matrix Online (officially abbreviated as MxO) was a massively multiplayer online role-playing game (MMORPG) initially developed by Monolith Productions and later, a few months after launch, by Sony Online Entertainment. <P2-S1>  It was billed as an official continuation of the storyline of "The Matrix films", as The Wachowskis, the franchise's creators, gave their blessing to the notion of gamers "inherit[ing] the storyline". <P2-S2>  The game began closed beta-testing in June 2004 which was then opened for people who pre-ordered the game in November 2004. <P2-S3>  Warner Bros. and Sega officially released "MxO" on March 22, 2005 in the United States. <P2-S4>  It was released in Europe on April 15, 2005. <P2-S5>  In June 2005 it was announced that Warner Bros. sold the rights to the game to Sony Online Entertainment, and the game's development and operation was transitioned to the latter on August 15, 2005. <P2-S6>  Sony Online Entertainment shut down operation of the game on July 31, 2009. <SEP> <P3-S0> Lana Wachowski (formerly Laurence "Larry" Wachowski, born June 21, 1965) and Lilly Wachowski (formerly Andrew Paul "Andy" Wachowski, born December 29, 1967) are American film directors, screenwriters, and producers. <P3-S1>  They are siblings, and are both trans women. <P3-S2>  Collectively known as The Wachowskis ( ) and formerly as The Wachowski Brothers, the pair made their directing debut in 1996 with "Bound", and achieved fame with their second film "The Matrix" (1999), a major box office success for which they won the Saturn Award for Best Director. <P3-S3>  They wrote and directed its two sequels: "The Matrix Reloaded" and "The Matrix Revolutions" (both in 2003), and were deeply involved in the writing and production of other works in that franchise.