Cartoonists are retiring their strips now because they can, because they own them. And because maintaining the quality of strips such as "FoxTrot," "Doonesbury" and "Calvin and Hobbes" isn't easy. These aren't gag-a-day strips. In addition to the daily dose of humor, there's character development, narrative arcs and, in the case of "Doonesbury" and "Boondocks," the struggle of staying topical.

Watterson ended his wildly popular "Calvin and Hobbes" in 1995, he has said, in part to avoid the inevitable drift into "halfhearted repetition" — the fate of many long-running comic strips.

Larson retired "The Far Side" the same year. Earlier, he had taken a 14-month leave to travel and study jazz guitar. He had drawn more than 4,000 cartoons since the cartoon went into syndication in 1979. Since "retiring," Larson has made animated films and published books.

Lee Salem, president of Universal Press Syndicate, dangled the possibility of "FoxTrot" popping up later in another form, such as animation. "In addition to Sunday newspapers, we may see "FoxTrot" entertaining us in other kinds of media platforms," he said in a statement posted on the company's Web site.

A spokeswoman for the syndicate wouldn't confirm that plans are in the works for a "FoxTrot" movie or TV series, saying only that it's "too early" to discuss it.

Amend, she said, is "not doing interviews," and Salem didn't care to elaborate on the statement.