instead showed that the computer could simulate a rich virtual world, and helped lay the foundations of video game concepts around exploring, collecting objects, and overcoming problems. Nick Montfort, in his book on interactive fiction Twisty Little Passages: An Approach to Interactive Fiction (2003), suggested that Zorks legacy and influence lay not in its parser or writing, but in the way it modeled the game world as a complex, dynamic space that the player moved through. Janet Murray, in Hamlet on the Holodeck (1997), considered this a result of the way the game was programmed compared to other games of the time, with each area, item, and actor modeled as their own object that could act and be acted upon. Historians have argued that Zork, along with Colossal Cave Adventure, influenced the creation of the MUD genre, and through it the more recent massively multiplayer online role-playing game genre. Zorks natural language parser has been noted as having a strong personality, and one of the first games to have one. It has been cited as starting a strong trend in writing for adventure games having "metafictional humor, and tendency towards self-parody". Decades later Zork is still cited as an inspiration for text interfaces such as chatbots. It has also been used, along with other text adventure games, as a framework for testing natural language processing systems. Zork was listed on several lists of the best video games more than a decade after release. In 1992 Computer Gaming World added Zork to its Hall of Fame. It was placed on "best games of all time" lists for Computer Gaming World and Next Generation in 1996, and Next Generation listed the entire series as a whole in 1999. In 2016 PC Gamer ranked Zork as one of the fifty most important video games ever made for establishing Infocom as a studio and defining an entire generation of adventure games. In 2007 Zork was listed among the ten "game canon" video games selected for preservation by the Library of Congress. Zork was the centerpiece of Infocom's game catalog, and Infocom quickly followed it with several more text adventure games using variants of the Zork codebase and the Z-machine, each of which sold tens of thousands of copies. By 1984, three years after Infocom began self-publishing Zork I, Infocom had fifty full-time employees, US$6million in annual sales, and twelve other games released. Infocom internally