(Fortune Magazine) -- The creators of "South Park," Matt Stone and Trey Parker, don't make life easy for their bosses at the network. Here are some of the things that have happened recently behind the scenes:

The U.S. Conference of Bishops complained to Tom Freston, then-CEO of Viacom (Charts), Comedy Central's corporate parent, about a "South Park" episode in which a statue of the Virgin Mary seemed to be miraculously bleeding; the two men accused Comedy Central of caving in to pressure when it pulled a rerun of "Trapped in the Closet," a show making fun of Tom Cruise and his involvement in the Church of Scientology; and Stone boasted to a men's magazine that he and Parker were tripping on LSD when they attended the Academy Awards in 1999 in gowns like the ones Gwyneth Paltrow and Jennifer Lopez had worn the previous year.

How dare they? Inspired by a classic Fortune portrait, Parker (left) and Stone impersonate CEOs.

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How to keep a comic edge 1. Don't think about a joke too long. You may start to hate it. 2. Don't delegate. "South Park's" second season suffered because Stone and Parker let the staff write scripts. 3. Think funny first, message later. "Our job is to make people laugh," says Parker. 4 Always push the boundaries of taste. "It's a total charge for us to say, 'Look what we got on TV. That's awesome!' "

Media companies generally don't tolerate this sort of behavior for long. But Parker and Stone's animated sitcom about foul-mouthed 8-year-olds Stan Marsh, Kyle Broflovski, Kenny McCormick and Eric Cartman growing up in a fictitious Colorado town is crucial to Comedy Central.

Before "South Park's" debut on Aug. 13, 1997, Comedy Central was a not-so-funny network that showed reruns of "The Benny Hill Show" and "Absolutely Fabulous." "South Park" made the Viacom subsidiary a cable industry power almost overnight. Comedy Central, which owns 100 percent of it, doesn't release "South Park's" financial results. But ten seasons later, the show is one of its most valuable franchises.

"South Park" is Comedy Central's highest-rated program, attracting 3.1 million viewers an episode, more than "The Daily Show with Jon Stewart." Last year, according to TNS Media Intelligence, it generated $34 million in advertising revenue.

In 2004, Comedy Central sold the syndication rights in a deal said to be worth $100 million. But "South Park's" real value may lie in the future - particularly in new media, where the show performs spectacularly. It dominates the iTunes top 100 television show downloads list. Amp'd Mobile, a cell phone service provider, is in discussions to launch a 24/7 "South Park" channel for its customers.

But that future value will depend on Parker and Stone and on whether they can keep their outrageous edge. Some people will always think of "South Park" as the show that brought fart jokes to basic cable. This is the show that began with a pilot titled "Cartman Gets an Anal Probe." "Most of the alleged humor on the premiere is self-conscious and self-congratulatory in its vulgarity: flatulence jokes, repeated use of the word 'dildo' (in the literal as well as pejorative sense), and a general air of malicious unpleasantness," wrote Washington Post TV critic Tom Shales.

It was clear to many other viewers, though, that "South Park" was the first great post-Simpsons animated comedy. An entire generation embraced the show in the late 1990s because it was hilarious.

Stan was so in love with his classmate, Wendy Testaburger, that he threw up every time she came near. Kenny died gruesomely every episode and was often devoured by rats. Jesus hosted a talk show on local cable. Satan was a sensitive gay man who agonized over his relationship with Saddam Hussein. From the start, no celebrity or politician was safe. Stone and Parker understood the subversive power of animated comedy: If a victim complained, they could say, "Hey, it's just a cartoon."

But even the greatest shows eventually jump the shark. The phrase itself, now a metaphor for decline, derives from TV comedy: An infamous "Happy Days" episode, in which Fonzie eluded a shark by leaping over it on water skis, signaled to the world that the writers had lost their spark.

It happened to "All in the Family" after its sixth season. Jerry Seinfeld has said publicly that his show was "crawling" by its sixth season. It has been argued that the last great season of "The Simpsons" was the eighth.

"South Park", though, now in its tenth season, is as sharp as ever and keeps getting better. Stone and Parker have transformed it from a show about fart jokes to a show about, well, fart jokes and satire worthy of Jonathan Swift (who wasn't above putting fart jokes into "Gulliver's Travels").

This ranges from sending up Paris Hilton and Mel Gibson to touching on the 2000 presidential election, 9/11 and Hurricane Katrina. Last year "South Park" won an Emmy for "Best Friends Forever," a show inspired by the Terry Schiavo controversy. In June, "South Park" won a Peabody Award for its "stringent social commentary."

When they started out, Stone and Parker knew how to make shows that were funny and shocking. Now they have become two of television's best storytellers. Their show's unusually tight production schedule has also kept them from wandering off into shark-infested waters. Like college students, Parker and Stone can't seem to get anything done until the last minute. It's not that they aren't lazy. They are. But "South Park's" creators say this is the only way they know to be funny.

People at South Park Studios in Marina Del Rey, Calif., call the writers' room "the source of great joy or the source of great sorrow." This seems to be a sorrowful day. The show's creators are sitting at the room's long table, unshaven and tired-looking. Parker appears to be under a great deal of stress.

It is a Monday afternoon in April, and they are rushing to finish an episode that will air Wednesday night. They have yet to come up with a first or last scene. The rest of the episode seems to be up in the air too. "I had a radical idea last night that totally changed the whole show," Parker says.

It would be a disaster for any other animated series. You won't find "Simpsons" creator Matt Groening tearing apart his show at the last minute. That show's writers labor over scripts and then send them off to be animated in South Korea. The entire process, typical of modern animation, takes eight months.

Parker and Stone, however, produce each of their shows in a week. They start Thursday morning with a writers' meeting and finish the following Wednesday, when they send the show to Comedy Central via satellite uplink hours before it airs at 10 P.M.

Anybody expecting television's reigning bad boys to be maniacs will be disappointed. They look pretty conventional these days. Stone, 35, shed his giant 'fro years ago. Parker, 36, has washed out the wacky highlights in his hair that made him look a little like Jeff Daniels in Dumb & Dumber. He got married earlier this year at his home in Hawaii. There was, however, a "South Park"-like twist: Parker and his wife, Emma Sugiyama, were married by the famed '70s sitcom producer Norman Lear. Parker, an accomplished singer, entertained his guests with karaoke renditions of Neil Diamond songs. ("Son of a bitch," Lear told me. "He's good.")

Despite their deadline pressure, the two men are affable and polite as they explain how their show is put together. The last thing they want is a year to work on it; if they kick an idea around too long, they will start to hate it. "Once you have a moment to second-guess yourself, we would just sit around and look at our stomachs for a month," Stone says. "It's better this way."

"I think that's also why the show feels right from the source, because it's not super-refined," says Parker. "It's the first things that come to mind that end up in there."

The show is done almost entirely in-house by Parker, Stone and their staff of about 70 people. There is enough computer animation technology in the studio to remake "Finding Nemo." But early on they hired a software consultant to make the computers "retarded," as one "South Park" veteran puts it, so that shows would have the same homemade look as the crude cartoons Parker and Stone made in college with construction papers and scissors.

Stone and Parker often come in the day after one show airs with no idea what the next will be. "Almost always our best shows are the ones we come up with the idea on Thursday," says Parker. "You go, 'What about this?' And boom, you just go with it."

On this particular day they are working on an episode titled "A Million Tiny Fibers," and they have been thinking about it too long. They decided back in February to have fun with the story of James Frey, who was excoriated on TV by Oprah Winfrey after admitting that parts of his best-selling memoir about substance abuse, "A Million Little Pieces," were fabricated.

"A Million Tiny Fibers" was supposed to start with a recurring character called Towelie - a talking, pot-smoking towel - on skid row using crack. His friends would confront him about his substance abuse; Towelie would clean himself up and write a Frey-like book but find that publishers weren't interested in a towel's memoir. So he would put on a bowler hat and a fake mustache and pretend to be human. Oprah Winfrey would embrace Towelie and his book, then skewer him on learning of his ruse.

But with 48 hours to go before air time, Parker wants to throw out the intervention and have Towelie remain a pothead throughout the show. The animators have to redo completed scenes to redden Towelie's eyes. Much of the dialogue has to be changed.

While "South Park's" attempt at literary satire is in need of an overhaul, Stone and Parker are delighted with a silly, scatological subplot about some of Oprah's body parts, which talk to each other in British accents. They cook up a scheme to get Oprah fired by revealing Towelie's identity to Geraldo Rivera.

You might think this subplot would make the people at the standards and practices department nervous - the "Oprah Winfrey Show" is distributed by a division of CBS, a company that, like Viacom, is controlled by Sumner Redstone. But Stone says "South Park" has talked to them about it. "Most of the time I actually like the standards people we work with," Stone says. "They are pretty reasonable. They have a really hard job."

Doug Herzog, president of Comedy Central/Spike TV/TVLand, says much the same of Parker and Stone: "They are great guys to deal with. They are artists, for sure, but they are also businessmen."

During my visit to South Park Studios, Parker appears to be the show's primary funny guy. He writes the scripts, directs the episodes, and provides the voices of Stan and Cartman. Stone does the voices of Kyle and Kenny, but you might call him the duo's external-affairs director. He handles the business aspects of the show that don't interest his partner.

So why do they share equal billing? "Trey physically writes the scripts," says Anne Garefino, executive producer of the show. "But it's Matt and Trey's voice."

Jason McHugh, who went to college with the two men and worked on "South Park" in its early days, says, "Usually Trey is the starter and Matt's the chimer-inner. But together they will riff out and beat down a joke and turn it inside out and go upwards, backwards, downwards, beat it until it's not funny anymore, and then it's even funnier than you ever could have imagined."

Parker has been shocking audiences since he was a boy growing up in Conifer, Colo. "When I was in sixth grade there was a talent show, and I wrote my first sketch, 'The Dentist,' " Parker told David Letterman in a March appearance on Late Night. "I played the dentist, and I had my friend play a patient. It was sort of what can go wrong at the dentist, and I just remember I had lots of fake blood and everything. Finally his head explodes. My parents got a call from the school; they were really upset. The kindergartners were all crying and freaking out."

Parker went off to the University of Colorado at Boulder, where he met Stone, a math prodigy from Littleton, Colo. The two collaborated on a short cartoon called "The Spirit of Christmas: Jesus vs. Frosty." It's really the first "South Park" episode, and you can find it today on YouTube. Kyle, Kenny, Cartman and Stan make a snowman. He comes to life and kills one of the boys. "Oh, my God," Stan says. "He killed Kenny!" "You bastard!" yells Kyle. The boys summon the baby Jesus, who throws his halo at Frosty like a Frisbee, decapitating him.

Stone and Parker spent much more time on a feature-length musical film about Alferd G. Packer, the 18th-century cannibal who ate members of his prospecting team after they ran out of provisions in the Rocky Mountains.

After college, the two went off to Hollywood in hopes of making more movies. Brian Graden, then an executive at Fox, put Stone and Parker to work making a pilot for a musical children's television series called "Time Warped." The pilot, called "Rom and Jul," was a love story about a Homo erectus and an Australopithecus.

Fox took a pass. But Graden paid Stone and Parker $1,200 to make a new version of "The Spirit of Christmas" he could send out as a Christmas card. It was probably the first viral video. George Clooney reportedly made 300 copies for friends. Comedy Central's Herzog saw it too. "It literally was the funniest thing I'd ever seen," he recalls. "We said, 'Develop a show.' So they went off and developed the show."

Nobody was prepared for what happened next. In its first season "South Park" made the cover of Newsweek and Rolling Stone. John Malone's Denver-based TCI, the nation's largest cable operator at the time, had recently dropped Comedy Central. When "South Park" debuted, the Denver newspapers and radio stations lambasted TCI for not having the hit show by two local guys. "The public went nuts," says Herzog. "We added about ten million TCI homes over the next 14 months, which at that time was unheard of."

Things were chaotic at South Park Studios too. Stone and Parker were producing the show in a cramped office suite below a sperm bank. After turning in shows on Wednesday, they would fly to Las Vegas with staff members for a night of debauchery and return to work the next day.

Parker and Stone had huge fights with the network. "That's all we've done since the first season, since doing the episode 'Stan Has a Gay Dog,' " says Stone. "It was a struggle to get them to understand the humor."

The two men won critical acclaim in 1999 when Paramount released "South Park: Bigger, Longer & Uncut," a musical film about how America declares war on Canada after the boys finagle their way into a R-rated movie from north of the border. The movie was nominated for an Academy Award for best song - "Blame Canada."

Soon viewers were turning to "South Park" for the same kind of satiric take on current events that they got from Jay Leno's monologue or "The Daily Show's" fake newscasts. In "Osama Bin Laden Has Farty Pants," the boys are captured by al Qaeda in post-9/11 Afghanistan. In "Two Days Before the Day After Tomorrow," Cartman and Stan accidentally destroy "South Park's" biggest beaver dam, causing a Katrina-like flood. In "The Passion of the Jew," Cartman tries to rid "South Park" of Jews after seeing "The Passion of the Christ."

Surprisingly, there hasn't been much backlash from celebrities who have been put through "South Park's" wringer. The exception was the controversy that ensued after "Trapped in the Closet" made fun of Tom Cruise and Scientology. Scientologist Isaac Hayes, the voice of Chef, "South Park's" lusty lunchroom cook, quit in protest. Stone and Parker complained that Comedy Central pulled a rerun of the show in March because of pressure from Cruise; both the network and Cruise deny this.

"Trapped in the Closet" was nominated for an Emmy in July. The network showed its appreciation by running a full-page ad in Variety with the "South Park" boys saying, "C'mon, Jews! Show them who really runs Hollywood." The episode has been rerun many times since.

Cruise hasn't done so well. In August, Viacom ended Paramount's relationship with Cruise, citing the actor's erratic behavior during the "Mission Impossible: III" publicity campaign. The incident speaks volumes about the changing balance of power in Hollywood: In the digital era, a franchise like "South Park" is more important than big-budget star vehicles like the "Mission Impossible" series.

At this year's Peabody Awards, host Jon Stewart seems genuinely thrilled when he announces "South Park's" prize. "They've been on the air for ten years, and it just keeps getting funnier and more relevant and more interesting," he says. "It's also one of the only two programs honored with a Peabody that focused entirely on Oprah Winfrey's talking vagina. The other one is "Nightline's" investigative series."

Parker accepts the award, moves to the microphone, and says, "When Matt and I first started making 'South Park', we asked ourselves two questions: What is socially responsible broadcasting, and how can artists provoke a call to change?"

The crowd chuckles nervously. "Why is that so fucking funny?" Stone snaps.

Backstage, Parker is candid when reporters ask him how it feels to win a Peabody. "It's not cool," he says wearily. "It's not punk rock."

If Stone and Parker seem a little paranoid, they should. They are under contract with Comedy Central to do two more seasons. How do they make it to 2008 without jumping the shark? Parker himself recently said he goes into every season thinking, "I should have quit."

Take, for instance, the last show of the eighth season. "I was just, like, fried," recalls Parker. Thursday went by without an idea, and he sent the staff home. On Friday night he called Anne Garefino and said, "Okay, Anne, you're going to have to call Comedy Central and tell them they don't have a show this week."

On Saturday morning, however, Parker and his staff had an inspiration: Why not do an episode about how Stan tries to help some cute forest animals? And the critters turn out to be devil worshippers and perform a ritual sacrifice? And cover themselves in blood and have an orgy?

The episode was "Woodland Critter Christmas," "South Park's" contribution to the holidays. Watch it, and you're likely to have several reactions: One, this is demented; two, it's hard to believe it is on television; and three, it's hilarious. Strange and unsettling things happen when a television show comes together in seven days or less. As long as "South Park's" creators remember that, they'll be fine.

Gallery: 'South Park's' rise to fame