The fall Calvin Klein (search) collection made the most of the label's tradition of clean, geometric lines, and Zac Posen's snake-themed collection got a standing ovation from many in the audience at New York Fashion Week.

At Calvin Klein, Francisco Costa, who took over design duties almost two years ago, proved Thursday that there is room on the runway for both the aesthetic set by the founding designer and Costa's own vision.

A black cashmere-sequin strapless dress with a a grid pattern was classic Calvin yet it also was contemporary — and it likely will be a leading look for fall. The geometric theme was seen in other styles as well, including a sheared mink grid coat, a strapless satin-chiffon bustier dress with an origami-inspired sash and a pleated skirt, and a silver duchesse satin reverse-pleat dress with spaghetti straps.

Another outstanding outfit was an architectural yellow satin strapless gown with a cutout back.

Costa's dresses were the strongest part of the runway show at a crowded downtown Manhattan studio. Actress Catalina Sandino Moreno (search), who is nominated for an Oscar for "Maria Full of Grace," sat in the audience.

Linda Wells, editor in chief of Allure magazine, said it was Costa's "thoughts of construction and deconstruction" that reminded her of Klein, who watched the preview alongside the fashion press and retail buyers.

Wells also noted Costa's precision and attention to details. "The grid was very unusual but it was an idea that was carried through in cashmere, fur, sequins and organza," she added.

Hip-hop mogul Russell Simmons led the applause at Posen's filled-to-capacity show at the Bryant Park tents, which for the last seven days have been the epicenter of the fashion world. Claire Danes, Ashley Olsen, Anne Hathaway, Bette Midler and Sean "P. Diddy (search)" Combs, an investor in Posen's business, helped fill out Posen's front row.

Posen's looks were creative yet wearable, and those featuring a metallic gold snake embellishment were stunners. They included a silk blouse paired with knickers and a bronze-colored silk halter gown.

As with Costa, dresses proved Posen's strong suit this season, particularly a dance dress with chevron pleats and a lilac gown with low cowls in the front and back.

Blouses have been all over the runways during Olympus Fashion Week, but Posen's poet blouse in pale blue silk was fresh and unique.

The vibe at Posen's show was hip and edgy, while Vera Wang's presentation, shown at the same venue earlier in the day, had a calmness and elegance to it.

An all-over pleated cocktail dress in seafoam green tulle, styled in the spirit of Flemish painters, seemed to float, and slim silver brocade pants with a long, slouchy sweater was an outfit one could picture the petite designer wearing.

But Wang is best known for her gowns, and among her best designs for fall were a teal and bronze brocade tank with a beaded band around the empire waist and a jade satin gown with ruching at the bust and back and two gold beaded belts, one thick, the other thin. A one-shoulder pleated purple gown was lovely in its delicate details.

"Through the illumination of color and their extraordinary handling of detail, Flemish painters celebrated beauty and sophistication," Wang wrote in her notes.

The one inexplicable look: the fur bonnets worn by some of the eveningwear models.

Fashion Week was to finish up Friday with Jennifer Lopez's debut at the tents as the finale.