TO A GENERATION OF EUROPEANS, Moncler was known as the premier maker of winter-weather performance jackets. Whether summiting a Himalayan peak or whooshing down the slopes at Verbier, its signature quilted garments were instantly recognizable, reliable against the cold—and had a cumbersome bulk that seemed best suited to life in the mountains. But this October in Paris, on a gray day during fashion week, a newly reimagined Moncler sent white-mesh hot pants and chiffon cocktail dresses down the runway as buff male models in tiny briefs clustered around a fake pool, performing calisthenics. The effect was a psychedelic homage to the beach culture of southern Italy—and a far cry from the old-guard alpine world Moncler once represented. Such departures from precedent aren't always greeted kindly, particularly when the fashion line in question is breaking from its own tradition. But for Moncler, the gamble is clearly paying off. On the eve of its 60th anniversary, the brand has never been more sharply noticed—or more admired—than it is today.

Moncler was founded in 1952 in Monestier de Clermont (the company name is a portmanteau), a French mountain town near Grenoble where René Ramillon, an entrepreneur and climbing enthusiast, began making quilted sleeping bags, tents and jackets to protect wearers from bitter temperatures. Early generations of Moncler jackets might have warmed climbers on the world's tallest peaks and downhill racers at the Olympics—and the subsequent boom in winter sports tourism of the 1970s helped catapult the label to cult status among the cliquish ski towns of the Alps—but its consumer base remained small and essentially European. The brand was respected, luxurious and static.

The mastermind behind the recent metamorphosis is the company's chairman and creative director, Remo Ruffini, who purchased Moncler in 2003. The company has thrived under his decade of leadership. At the time he took over, Moncler was "only one jacket," says Ruffini, 51, who was born in Como, Italy. "That jacket was used for making expeditions to the Himalayas, Karakorum, Alaska—but you only used it two or three times a year, and it was very heavy," he says. "That's why I started from there, from the perception of the brand." Ruffini's blueprint for reviving Moncler has centered on improving both quality and visibility. The former means sourcing the best goose down from France, the best fabric from Japan and locating the lightest zippers. (Rendering an ultra-warm feather jacket airy and formfitting is perhaps Moncler's foremost achievement.) "Quality is important," says Ruffini, "and you need good technology to have good quality."

The latter part of Ruffini's plan presented the greater challenge. How to reinvent a fusty if beloved company while honoring its history and appeasing longtime customers? Part of the answer has been found in savvy collaborations with fresh designers—a strategy successfully deployed by brands that were once similarly deadlocked, like J. Crew and Brooks Brothers. Under Ruffini's direction, Moncler has joined forces with everyone from Giambattista Valli for the womenswear-based Gamme Rouge collection and Thom Browne for the Gamme Bleu menswear collection, to Japanese designers Comme des Garçons and Chitose Abe. "I'm looking for designers who have roots," says Ruffini. "If you think about Thom Browne, he starts from a gray suit. Valli starts from the couture of the '50s and '60s—something very elegant and classic." These partnerships have produced more than new designs for coats; clients can now wear head-to-toe Moncler, anytime of the year.

If quality and cool collaborations have provided Ruffini with a solid base for rebranding, his immersive, unapologetically giddy presentations have perhaps most directly altered how Moncler is perceived among the fashion set. Last year, on a frigid night in February, nearly 200 professional athletes took to Wollman skating rink in New York's Central Park to perform synchronized routines on the ice wearing that season's Grenoble collection. The year before, 160 individuals formed a flash mob in Grand Central Terminal, where, to the sounds of Barbra Streisand and Prince, they executed a seven-minute dance routine inspired by Bob Fosse. Breaking from the mold is in every way Ruffini's intention, with the presentation of his shows and the direction of his company. More like performance art or musical theater, the spectacles offer a dose of levity—and form a lasting impression. "We haven't started yet, but I want to make something more different, more unique," Ruffini says of the fashion show he'll create for next spring. "Every season I design a collection with the presentation already in mind."