When production chiefs from selected studios trooped to Icon Prods. headquarters after an invite to read the film Mel Gibson planned for summer 2006, they were surprised at the very first page of the script. “The dialogue you are about to read will not be spoken in English.” Gibson, who last made the most successful Aramaic-language film ever, is at it again. “Apocalypto” hardly fits the traditional definition of a summer film. Set 500 years ago, the movie will be filmed in an obscure Mayan dialect, presumably with the same kind of subtitles Gibson reluctantly added to “The Passion of the Christ.” It will star a neophyte cast indigenous to the region of Mexico where Gibson will shoot in October. And it likely will carry an R rating, unless Gibson tempers the onscreen depiction of violent scenes he wrote in his script. Since Gibson’s bankrolling his movie and will sell foreign himself, studios were offered only a rent-a-system deal, such as George Lucas had with 20th Century Fox for his last three “Star Wars” films. And because “Apocalypto” is not a religious film, there’s no guarantee of an encore turnout of the church groups and hardcore Catholics who made “The Passion of the Christ” a nearly $1 billion box office/DVD bonanza. At least three studios passed on the project before Disney bought it. Nevertheless, the fact that more than one studio bid for the project shows Gibson’s viability and makes laughable last year’s prediction by the New York Times that Gibson would be blackballed by Jewish executives after the “Passion” controversy.