The festivities on opening night of the Public Theater’s production of “As You Like It” were just as I liked. Indeed, it’s hard to say what part of the event I liked best.

There was the glorious setting of Central Park; the thoroughly entertaining Shakespeare production, both ribald and sophisticated, and the impressive array of stage, business, and philanthropic talent gathered in one place. Really, they were everywhere: from Lauren Bacall to Rosie Perez, Lauren Veronis to Celerie Kemble, Donald Newhouse to Lachlan Murdoch, Mayor Bloomberg to Mark Green.

The thing I liked best, though, was the buoyant mood of the party. Burdens were light or forgotten. Fashion was frivolous, colorful. At midsummer there is nothing more heartening in New York City than Shakespeare in the Park, bringing hundreds of New Yorkers together for free entertainment under the stars.

And this is an important year to celebrate it, as the Public Theater marks its 50th anniversary. Creating a sense of community in this big town has been a part of the Public Theater’s mission from the start. Joseph Papp started out with an ensemble performing Shakespeare on a flatbed truck, usually in parks throughout the five boroughs. Now, the artistic director, Oskar Eustis, and the executive director, Mara Manus, oversee Shakespeare in the Park, Joe’s Pub, and original productions at the theater at 425 Lafayette St.

Back to the party: I caught my glimpse of Ms. Bacall as folks were pouring out of the Delacorte. Had my evening ended then, I would have been content to walk home, holding my bulls-eye seat cushion, courtesy of Target, and thinking silly and romantic thoughts inspired by the final scene and the starry summer night.

But there was more. Up the path to Belvedere Castle I went to dance under the stars, next to members of the cast and their significant others, including the actress who plays Rosalind, Lynn Collins, and her boyfriend, Keanu Reeves. I learned the two are set to appear together in the upcoming romantic film “Il Mare.” But Ms. Collins reserved her most enthusiastic display of affection for fellow cast member Jennifer Ikeda, with whom she did some very close dancing.

Other cast news: After “As You Like It,” Richard Thomas, who plays the jester Touchstone, is traveling to Los Angeles to film a Hallmark family movie, and Michael Esper, who has the role of the shepherd Silvius, will start rehearsals for the Playwrights Horizons production of Sarah Shulman’s new play, “Manic Flight Reaction.” Mr. Esper, who brought his sister Shannon Esper to the party, reports he is “not in love at the moment.”

I also met an R&B and soul singer, Malissa Hunter, who is working on a self-titled CD and will be performing at Hiro on July 28; the photographer Eric Johnson, and the three Mosquea sisters from the Bronx, who are earning minimum wage as ushers at Shakespeare in the Park, Leocadia, 21, Kirsy, 18, and Maury, 16.

“I’ve seen the production 27 times now. I know all his lines and he still cracks me up,” the eldest Ms. Mosquea, an undergraduate at Penn State, said.