Each summer, as the nights grow longer and lazier, numerous New York film programmers organize outdoor movie screenings in the hopes of attracting filmgoers who would otherwise rebuff the confines of a theater on a gorgeous summer night. But few of these groups have their sights set as high as Rooftop Films, which delivers to fans a summer-long schedule on a scale few others can match.

More than 2,500 submissions flow in to its organizers on a yearly basis, all sent by filmmakers hoping for the chance to headline an outdoor show. Their interest is stoked by the ever-increasing size of Rooftop crowds; this year, between June and September, an estimated 20,000 viewers will take part in the group’s 38 planned events.

“More than just the fun of being outside, I think we show some of the best motion picture entertainment out there, whether we’re talking short films, animated films, comedies, documentaries, even home movies,” Rooftop Films’s founder and artistic director, Mark Elijah Rosenberg, said. “What’s really amazing, though, is the way that the different audiences interact with the movies. We’re doing screenings all around the city — in East Williamsburg, in Harlem, in Chelsea, in Williamsburg, in Gowanus. To a large degree, the audiences really do reflect the neighborhood, and affect the way we set out to program a given evening.”

Since the group’s inaugural event in 1997, hundreds of thousands of New Yorkers have come in contact with the efforts of Mr. Rosenberg and his growing circle of associates. Part of the event’s appeal seems to b e its sheer simplicity: Every weekend, a few dozen or a few hundred people gather on a roof to see a handful of films, hear a few tunes performed live by visiting bands, and, on select occasions, share a few drinks at Rooftop after-parties. This year, the season’s 38 evenings will be divided among feature films and showcases of shorts programs. In total, Rooftop Films plans to recognize 19 features and more than 150 shorts.

The 2008 season begins in earnest this weekend with two events scheduled at the Open Road Rooftop, atop the New Design High School on Manhattan’s Lower East Side. Promoted as a two-day “film, music, and graffiti festival,” the screenings will also serve as a fund-raiser to aid New Design in preserving its threatened arts program.

In the following weeks, the Rooftop programs will move to Williamsburg (June 12), Gowanus (June 14), the East Village (July 4), and beyond. Mr. Rosenberg said he is especially excited by some of the more daring themes included in this year’s programs.

“Our opening night program is all about friends and people partnering together,” Mr. Rosenberg, who was evicted from his apartment in 1997 after staging the original, impromptu rooftop screenings with a 16 mm projector and a bedsheet, said. “There’s also a romance show that I’m really excited about, and a program we’ve organized with the Museum of Modern Art comprised of surreal films inspired by Salvador Dali.” That program, dubbed “Surreal Shorts,” is scheduled to screen on the Lower East Side on June 27.

As the crowds and the lineups have grown, so have the partnerships piled up for Rooftop Films, including pacts with IFP and indieWIRE. And last summer witnessed the beginning of a special affiliation between Rooftop and IFC Center. Throughout the summer, IFC will host shorts from various Rooftop programs on its Web site (which can be accessed through RooftopFilms.com), making them accessible to online audiences around the world. Even more important to independent filmmakers, thanks to donors, grants, and sponsorships — as well as ticket sales — Rooftop Films now awards a select number of grants to independent filmmakers to help develop their shorts and features. One dollar from every ticket sold during the summer season — and $1 from every submission fee paid by filmmakers — is reinvested into filmmaking grants.

Benh Zeitlin is one of the beneficiaries of last year’s grants. Having previously shown his work through Rooftop Films — his short film, “Egg,” a surrealist take on the famous tale of “Moby Dick,” and his time-warping short “The Origins of Electricity” both shown at Rooftop events — he received a $1,200 grant to help him develop the short film that would eventually be called “Glory at Sea!” which won a special jury prize at the Boston International Film Festival and will enjoy its premiere June 12 in Williamsburg.

“‘Glory at Sea!’ is this adventure story set in an apocalyptic, almost post-Katrina New Orleans, about a community coming together,” Mr. Zeitlin said. “It eventually ended up costing $100,000, as our plans grew more complicated and we added characters, so the grant was just a drop in the bucket. But what the grant did is hold me accountable. People were expecting and were excited about a product, and it sort of pushed me forward, their enthusiasm.”

While it was the money that made this year’s project particularly special, Mr. Zeitlin said he has always been a fan of the way Rooftop Films gives equal treatment to short films while celebrating them in an unconventional setting.

“There’s really no good way to see short films. At festivals, they are treated as a second-class event, and it’s a bit unclear what genres and groups shorts fit into,” Mr. Zeitlin said, recalling his film-school days, when he would shoot shorts and then borrow projectors to screen them for friends. “But to take shorts out of the normal context of going to a movie theater, to offer a different kind of experience, I think it helps audiences watch these kinds of films in different ways. That’s what Rooftop Films does. It helps you to see these stories in a whole new light.”

ssnyder@nysun.com