Kids’ nets grow globally | U.S. kid shows have firm hold overseas | Preschool programs cautious about 3D | Music-filled shows gain momentum worldwide | Long-running kids shows keep pace | Mip Junior was honey for ‘The Hive’

You know a TV show’s been around a long time when original viewers’ kids make up most of its audience. For “Sesame Street” — entering season 41 — some current fans are third-generation viewers.

Kids today are savvier than just five years ago, so how have long-running kids shows kept pace with an ever-changing audience?

“For many years, ‘Sesame Street’ was the only game in town as far as children’s television. We went a long time without having to evolve very much,” exec producer Carol-Lynne Parente says. “But the competition certainly stepped up their game, and the evolution of technology keeps changing. We’re in a position where television isn’t the only way kids can access content.”

Every successful kids show has a robust website, licensed goods and other ways of expanding its audience, but the shows themselves are still the strongest assets.

“The real environment of the neighborhood allows us to do difficult storylines,” Parente says. That realism helps viewers accept change, making new characters easier to accept. “Season 41 is a perfect example of that evolution with a new segment, Super Grover 2.0 — think Adam West’s Batman compared with ‘The Dark Knight.’?”

“Power Rangers” — recently re-acquired by Saban Brands, which debuted the series in 1993 — launches its 18th season in 2011. Lasting so long was no accident.

“After 2 1/2 or three seasons of ‘Mighty Morphin Power Rangers,’ we were at such a peak of popularity that we asked ourselves, ‘How do you take a phenomenon and convert it into an evergreen?’?” Saban Brands prexy Elie Dekel says. The answer: Risk it all, shake up the formula, but stay true to the original.

“We reinvented it while keeping it very much ‘Power Rangers,’?” Dekel says. “Every year the cast, costumes, sets and story mythology evolved. We now have 17 iterations of ‘Power Rangers.’ Each one carries the DNA of the original, yet each has its own distinction.”

“Dora the Explorer” and “SpongeBob Squarepants” are comparatively new, but both are still relevant after more than 10 years on the air.

“We really just set out to make ourselves laugh,” says “SpongeBob” exec producer Paul Tibbitt. “But there are certain things we never do. We don’t like to break the fourth wall or wink at the audience, and we don’t like to include pop culture references,” which instantly date an episode. “We want to maintain the show’s innocence and otherworldly feeling. These are pure, simple characters. If you stay true to them, you’re true to your intended audience.”

Each episode of “Dora” undergoes multitiered research with test groups of 3- to 5-year-olds.

“We’re very connected to our audience, which keeps us up-to-date and relevant,” “Dora” exec producer Valerie Walsh Valdes says. “We learned early on that comprehension equals appeal, so (we tell) a clean linear story with a strong heartline appeals to kids.”

Despite how worldly today’s kids are, they still respond to engaging characters.

“Kids have changed, but I don’t think their appreciation for stories has changed,” fellow exec producer Chris Gifford says. “The stories we’re telling now are stories we could have told 10 years ago with the same appeal.”