Attempts were made to adapt 1992's "Kamp Krusty" into a movie

"First of all, if we make it into the movie then we don't have a premiere, and second if we can't make 18 minutes out of this episode how are we supposed to make 80?"

Work began on a script for the film, and additional writers and animators were hired so that new episodes of the show and the film could be produced at the same time. Groening and Brooks invited Scully and showrunner Al Jean to produce the film with them. Former director and Pixar employee David Silverman was brought back to direct the film. A dream team of writers from the show's earliest seasons was assembled to work on the movie. Ian Maxtone-Graham, George Meyer, David Mirkin, Mike Reiss, Matt Selman, John Swartzwelder, and Jon Vitti all had a hand in the script in addition to Brooks, Groening, Jean, and Scully.

"The idea of the movie is that all of us who ran the show at one point and who have been there from the beginning come together as the writing team." - James L. Brooks, 12/8/2004

Work on the film's screenplay took place in the small bungalow where Groening first pitched The Simpsons to Brooks in 1987. The plot of the film was inspired by a news story Groening had read about a town whose water supply was actually tainted by pig feces. Before all was said and done, the film's script went through over 100 revisions. Animation for The Simpsons Movie began in January 2006, with the Itchy & Scratchy short being the first scene to be storyboarded. The film was produced in a widescreen 2.35:1 aspect ratio, to distinguish it from the look of the TV series, and colored with the largest palette Simpsons animators had ever had available to them. Brooks chose his good friend Hans Zimmer to compose the film's score. All of The Simpsons' regular voice actors and semi-regular performers reprised their roles as the characters in the movie. According to Groening, attempts were made to include every Simpsons character in the film, with 98 characters having speaking roles. The first of three table reads with the cast took place in May 2005, with Brooks directing the actors for the first time since the early 1990s. The recording sessions were much more intense than those done for the show, with some scenes such as Marge's video message to Homer being recorded over a hundred times.

The movie premiere in Springfield, Vermont

On April 1, 2006, 20th Century Fox announced that The Simpsons Movie would be released worldwide on July 27, 2007. Editing of the movie ran well into 2007, with some edits taking place as late as two months before the film was released. The film was rated PG-13 by the Motion Picture Association of America for "irreverent humor throughout". After a competition between 16 Springfields in the United States to host the American premiere, Springfield, Vermont was chosen and hosted the world premiere of The Simpsons Movie on July 21, 2007. A yellow carpet was used instead of the traditional red.

Meanwhile, Homer adopts a pig from Krusty Burger. Homer stores the pig's feces in a silo which Marge tells him to dispose of. However, Homer gets distracted and instead dumps the silo in the lake, polluting it again. Moments later, a squirrel jumps into the lake and becomes mutated. Nearby, Flanders and Bart discover the squirrel during a hike, and the EPA captures it. Russ Cargill, head of the EPA, presents five options to U.S. President Arnold Schwarzenegger to keep Springfield's pollution contained; he randomly picks the action of enclosing Springfield in a glass dome. When the police discover Homer's silo in the lake, an angry mob of townspeople approach the Simpsons' home and set the house on fire. However, the Simpson family escapes through a sinkhole and decides to flee to Alaska.

Cracks start to appear in the dome and Cargill, not wanting news of what he has done to become widespread, plans to destroy Springfield. In Alaska, the Simpsons see an advertisement for a new Grand Canyon to be located on the Springfield property. Marge and the kids decide to go and save the town, but Homer refuses to help the people who attempted to kill them. The family abandons Homer and leaves Alaska but are eventually captured by the EPA and placed back in the dome. After a visit from a mysterious Inuit shaman, Homer has an epiphany and believes he must save the town in order to save himself. As he arrives at Springfield to do so, a helicopter lowers a bomb suspended by a rope through a hole in the dome. Homer climbs to the peak of the dome and descends the rope, knocking down the escaping townspeople and the bomb. Homer grabs the bomb and a motorcycle. After reuniting with Bart, they cycle up the side of the dome and Bart tosses the bomb out through the hole, seconds before detonation. The bomb explodes, shattering the dome. The town praises Homer, who rides off with Marge on the motorcycle into the sunset. The townspeople begin the process of restoring Springfield back to normal.

"It will happen at some point, but I have no idea when. The first one took us four years – mainly because we don't like to work any harder than we usually do. It's going to be awhile. We'll get to it, I'm sure." - Matt Groening, 7/14/2008

"We would like to do a sequel but not unless we had a script that we believed in as much as that one. That one took fifteen years. It was a labor of love but it was also a labor of work, and that was fine." - Al Jean, 7/26/2008

Don't hold your breath, Simpsons fans. It'll be another several years - and perhaps not until the TV series ends - before we see The Simpsons Movie 2.