The story begins in Los Angeles in the 21st century, no longer part of the United States. The federal government of the United States has ceded most of its power and territory to private organizations and entrepreneurs. Franchising, individual sovereignty, and private vehicles reign supreme over the landscape. Mercenary armies compete for national defense contracts while private security guards preserve the peace in sovereign, gated housing developments. Highway companies compete to attract drivers to their roads and all mail delivery is by hired courier. The remnants of government maintain authority only in isolated compounds where they transact tedious make-work that is, by and large, irrelevant to the dynamic society around them.
Much of the territory ceded by the government has been carved up into sovereign enclaves, each run by its own big business franchise (such as "Mr. Lee's Greater Hong Kong", or the corporatized American Mafia) or the various residential burbclaves—suburban enclaves that were inspired by the quasi-sovereign gated communities legalized in California by the Davis–Stirling Common Interest Development Act.
This arrangement resembles anarcho-capitalism, a theme Stephenson carries over to his next novel The Diamond Age. As described in both novels and the short story "The Great Simoleon Caper" (1995), hyperinflation has sapped the value of the US$ to the extent that trillion dollar bills—Ed Meeses—are nearly disregarded and the quadrillion dollar note—the Gipper—is the standard 'small' bill. Hyperinflation encouraged people to use electronic currency which is exchanged in encrypted online transactions and is hence untaxable. For physical transactions, they resort to alternative, non-hyperinflated currencies such as yen or "Kongbucks" (the official currency of Mr. Lee's Greater Hong Kong). Hyperinflation has also negatively affected much of the rest of the world (with some exceptions like Japan), resulting in waves of desperate refugees from Asia who cross the Pacific in rickety ships hoping to arrive in North America.
The Metaverse, a phrase coined by Stephenson as a successor to the Internet, constitutes Stephenson's vision of how a virtual reality-based Internet might evolve in the near future. Resembling a massively multiplayer online game (MMO), the Metaverse is populated by user-controlled avatars as well as system daemons. Although there are public-access Metaverse terminals in Reality, using them carries a social stigma among Metaverse denizens, in part because of the poor visual representations of themselves as low-quality avatars. Status in the Metaverse is a function of two things: access to restricted environments such as the Black Sun, an exclusive Metaverse club, and technical acumen, which is often demonstrated by the sophistication of one's avatar.
Hiro Protagonist is a hacker and pizza delivery driver for the mafia. He meets Y.T. (short for Yours Truly), a young skateboard Kourier (courier), during a failed attempt to make a delivery on time. Y.T. completes the delivery on his behalf and they strike up a partnership, gathering intel and selling it to the CIC, the for-profit organization that evolved from the CIA's merger with the Library of Congress. Within the Metaverse, Hiro is offered a datafile named Snow Crash by a man named Raven who hints that it is a form of narcotic. Hiro's friend and fellow hacker Da5id views a bitmap image contained in the file which causes his computer to crash and Da5id to suffer brain damage in the real world. Hiro meets his ex-girlfriend Juanita Marquez, who gives him a database containing a large amount of research, positing connections between the virus, ancient Sumerian culture and the legend of Tower of Babel. Juanita advises him to be careful and disappears.
The Mafia boss Uncle Enzo begins to take a paternal interest in Y.T. Impressed by her attitude and initiative, he arranges to meet her and offers her freelance jobs. Hiro's investigations and Y.T.'s intelligence gathering begin to coincide, with links between the neuro-linguistic viruses, a religious organization known as Reverend Wayne's Pearly Gates and a media magnate named L. Bob Rife beginning to emerge. Juanita's research showed that the ancient Sumerian ur-language allowed brain function to be 'programmed' using audio stimuli in conjunction with a DNA altering virus. Sumerian culture was organized around these programs (known as me) which were administered by priests to the populace. Enki, a figure of legend, developed a counter-virus (known as the nam-shub of Enki) which when delivered stopped the Sumerian language from being processed by the brain and led to the development of other, less literal languages, giving birth to the Babel myth. L. Bob Rife had been collecting Sumerian artifacts and developed the drug Snow Crash in order to make the public vulnerable to new forms of me which he would control. The physical form of the virus is distributed in the form of an addictive drug and within Reverend Wayne's church via infected blood. There is also a digital version to which hackers are especially vulnerable as they are accustomed to processing information in binary form.
Hiro heads north to where the Raft, a huge collection of boats containing Eurasian refugees, is approaching the American coast. Rife has been using the Raft as a mechanism to indoctrinate and infect thousands with the virus and so import it to America. Y.T. is captured and brought to Rife on the Raft, who intends to use her as a hostage, knowing her connection to Uncle Enzo. With help from the Mafia, Hiro makes it onto the raft and recovers the nam-shub of Enki which Rife had been concealing. With help from Juanita who had previously infiltrated the Raft, the nam-shub is read out and Rife's control over the Raft is broken. Rife flees the Raft, taking Y.T., and Raven attempts to activate the digital form of Snow Crash at a virtual concert within the Metaverse. Hiro is able to neutralize the virus and Y.T. escapes. After a confrontation with the Mafia, Raven is injured, and Rife is killed as he attempts to flee on his private jet. Y.T. is reunited with her mother and Hiro and Juanita appear reconciled.
Various technologies are employed in this fictional world, and help define it. Among these are:
Rat Things, also known as semi-autonomous guard units, are cybernetic personal defensive guards found in and around Mr. Lee's Greater Hong Kong. Engineered from pit bull terriers surgically augmented with cybernetic components, Rat Things are named for their long, flexible tails.
Rat Things were invented by Mr. Ng, of Ng Security Industries, who was severely handicapped after a helicopter accident in Vietnam. Like the Rat Things, Mr. Ng is also a cyborg.
Rat Things remember their previous lives as dogs. They can also communicate with other Rat Things by "barking" in the Metaverse. Although their minds are largely controlled by their implants, they can sometimes act independently of their programming. When in the Metaverse and not performing guard duties, Rat Things experience running on endless beaches, playing in the surf, eating steaks that grow on trees, and blood-drenched Frisbees floating around, waiting to be caught.
Like other technology in Snow Crash, Rat Things are powered by a nuclear isotope battery, which requires extensive cooling due to the massive amount of waste heat generated. The Rat Things are passively cooled by a system of heat sinks that are only effective when the Rat Thing runs fast enough to move ambient air across the fins. To prevent rapid overheating when stationary, they must remain in their hutches (effectively dog houses), where they are continuously sprayed by jets of refrigerant. Through running, Rat Things are capable of breaking the sound barrier (about 768 mph at sea level), although this is not typically permitted by Mr. Lee's Greater Hong Kong's "good neighbor" policies due to noise reasons. Because they must be either moving at high velocities or actively cooling in their hutches, Rat Things are rarely seen by human eyes and few people know what they look like.
A fictional type of wheel prominently used on skateboards and advanced motorcycles. They consist of small segments of contact surface mounted on telescoping spokes, allowing the wheel to take the shape of cracks, curbs, and bumps. They have a passing mention in The Diamond Age as being used on a wheelchair belonging to a minor character.
Reason is a railgun in a rotary cannon configuration which fires depleted uranium flechettes. It is mounted to a large, wheeled ammunition box and is equipped with a harness for user comfort, a nuclear battery pack, and a water-cooled heat exchanger. The weapon, created by Ng, was still in beta testing, and suffers a software crash during a battle, resulting in the death of its user. Hiro is later able to apply a firmware update, and uses it until its ammunition supply is depleted. It bears, in inscription on its nameplate, the Latin phrase Ultima Ratio Regum, "the last argument of kings".
The Metaverse is a collective virtual shared space, created by the convergence of virtually enhanced physical reality and physically persistent virtual space, including the sum of all virtual worlds, augmented reality, and the internet. The word metaverse combines the prefix "meta" (meaning "beyond") with "universe" and is typically used to describe the concept of a future iteration of the internet, made up of persistent, shared, 3D virtual spaces linked into a perceived virtual universe.
Stephenson's Metaverse appears to its users as an urban environment, developed along a single hundred-meter-wide road, the Street, that runs the entire 65536 km (216 km) circumference of a featureless, black, perfectly spherical planet. The virtual real estate is owned by the Global Multimedia Protocol Group, a fictional part of the real Association for Computing Machinery, and is available to be bought and buildings developed thereupon.
Users of the Metaverse gain access to it through personal terminals that project a high-quality virtual reality display onto goggles worn by the user, or from low-quality public terminals in booths (with the penalty of presenting a grainy black and white appearance). Stephenson also describes a sub-culture of people choosing to remain continuously connected to the Metaverse by wearing portable terminals, goggles and other equipment; they are given the sobriquet "gargoyles" due to their grotesque appearance. The users of the Metaverse experience it from a first person perspective.
Within the Metaverse, individual users appear as avatars of any form, with the sole restriction of height, "to prevent people from walking around a mile high". Transport within the Metaverse is limited to analogs of reality by foot or vehicle, such as the monorail that runs the entire length of the Street, stopping at 256 Express Ports, located evenly at 256 km intervals, and Local Ports, one kilometer apart.
Snow Crash established Stephenson as a major science fiction writer of the 1990s. The book appeared on Time magazine's list of 100 all-time best English-language novels written since 1923.
Some critics have considered it a parody of cyberpunk and mentioned its satiric or absurdist humor.
In his book The Shape of the Signifier: 1967 to the End of History, Walter Benn Michaels considers the deeper theoretical implications of Stephenson's book. Comparing the book with a range of contemporary writers—the fiction of Bret Easton Ellis, Kathy Acker, Octavia Butler, and even Paul de Man and the literary criticism of Richard Rorty—Michaels criticizes the deep claims of Stephenson's book: "And yet, in Snow Crash, the bodies of humans are affected by "information" they can't read; the virus, like the icepick [in American Psycho], gets the words inside you even if you haven't read them." Michaels especially targets Stephenson's view that "languages are codes" rather than a grouping of letters and sounds to be interpreted. Michaels further contends that this basic idea of language as code ("... a good deal of Snow Crash's plot depends upon eliding the distinction between hackers and their computers, as if—indeed, in the novel, just because—looking at code will do to the hacker what receiving it will do to the computer") aligns Stephenson, along with other writers mentioned, with a racially motivated view of culture: that culture is something transmitted and stored by blood (or genetic codes), and not by beliefs and practices. According to critic Walter Benn Michaels:
The body that is infected by a virus does not become infected because it understands the virus any more than the body that does not become infected misunderstands the virus. So a world in which everything—from bitmaps to blood—can be understood as a "form of speech" is also a world in which nothing actually is understood, a world in which what a speech act does is disconnected from what it means.
Rorty's Achieving Our Country uses Snow Crash as an example of modern culture that "express the loss of what he [Rorty] calls "national hope"...the problem with Snow Crash is not that it isn't true—after all, it's a story—but that it isn't inspirational." This lack of inspiration is offset by something else Snow Crash and other works like it offer: "These books produce in their readers the 'state of soul' that Rorty calls 'knowingness,' which he glosses as a 'preference for knowledge over hope' (37)"; this preference for knowledge "contribute[s] to a more fundamental failure to appreciate the value of inspiration—and hence of literature—itself."
While the 1986 virtual environment Habitat applied the Sanskrit term avatar to online virtual bodies before Stephenson, the success of Snow Crash popularized the term to the extent that avatar is now the accepted term for this concept in computer games and on the World Wide Web.
Many virtual globe programs, including NASA World Wind and Google Earth, bear a resemblance to the "Earth" software developed by the Central Intelligence Corporation in Snow Crash. One Google Earth co-founder claimed that Google Earth was modeled after Snow Crash, while another co-founder said it was inspired by Powers of Ten. Stephenson himself has commented on the legacy of his "Earth" program's god's-eye aesthetic in his novel Reamde, in which his protagonist, a game designer, steals the technique from Google Earth:
The opening screen of T'Rain was a frank rip-off of what you saw when you booted up Google Earth. Richard felt no guilt about this, since he had heard that Google Earth, in turn, was based on an idea from some old science-fiction novel.
Software developer Michael Abrash was inspired by Snow Crash's Metaverse and its networked 3D world. He left Microsoft for Id Software to write something in that direction, the result being Quake. The story for the 3DO game Immercenary was also heavily influenced by Snow Crash.
Former Microsoft Chief Technology Officer J Allard and former Xbox Live Development Manager Boyd Multerer claimed to have been heavily inspired in the development of Xbox Live by Snow Crash and it was mandatory reading for the Xbox development team.
The novel was optioned shortly after its publication and subsequent success, although to date it has never progressed past pre-production. Vincenzo Natali, the director of several science fiction films, in particular has remarked against a two-hour feature film adaptation because of a perceived lack of fit with the form; inasmuch as the novel is "tonally all over the place", he feels that a mini-series would be a more suitable format for the material.
In late 1996, it was announced writer-director Jeffrey Nachmanoff would adapt the novel for the Kennedy-Marshall Co. and Touchstone Pictures. Marco Brambilla was attached to direct the film.
In June 2012, it was announced that English director Joe Cornish, following the debut of the 2011 film Attack the Block, had been signed as director of a future film adaptation for Paramount Studios. Stephenson has described Cornish's script as "amazing", but also warned that there is no guarantee the film will ever be made. In July 2016, producer Frank Marshall said that filming may start in 2017.