Lene Tsegay beamed from behind her cash register at the crowd mingling in the Kefa Cafe. Multicolored balloons bobbed near the ceiling of the sunlit space on Bonifant Street, its walls painted a soothing pale yellow.

"Oh, it's good they came," she said to herself as a man walked in, a little girl on his hip. Saturday was customer-appreciation day at the cafe, which Tsegay owns with other family members, and she greeted many regulars by name. Her voice mixed gratitude with relief that so many people had shown up.

Kefa Cafe may be a symbol of the Silver Spring ethos -- quirky, welcoming and multicultural -- and a treasure to its patrons, but the disruption of redevelopment and brand-name competition such as Starbucks have hurt the bottom line over the past two years. "What we expected to make and what we did make wasn't close to each other," Tsegay said. "Still, we're here."

Worries about the competition Kefa Cafe faces are part of a coded discussion of what Silver Spring will become: another Adams Morgan? A "junior Bethesda"?

Many people celebrate the public-private renewal effort led by Montgomery County Executive Douglas M. Duncan (D), which has turned a depressed business district into a mini-boomtown. A 22-acre core area, largely rebuilt in the past five years, includes a movie megaplex and several shops and eateries in a mall without walls.

The business district hosts two anchors of redevelopment: the headquarters of Discovery Communications and the American Film Institute's Silver Theater, a restored art deco showpiece. Yesterday, AFI and lead sponsor Discovery opened the third annual Silverdocs, a festival of documentary filmmaking.

On weekends, Ellsworth Drive closes to traffic and becomes something of a faux Main Street. Saturday night, kids raced through jets of water in the mosaic fountain that has become the centerpiece of the redevelopment. A clump of teenagers chatted in Spanish outside Chipotle, and a group carrying rainbow banners from the District's gay pride parade shared the curb near Borders with a young couple who had just bought Ben & Jerry's for their toddlers.

What a difference a decade makes. In the early 1990s, Albino Castro, whose Mi Rancho restaurant is a few minutes' stroll from the Silver Theater, had to escort customers to their cars at night "to make sure they were safe." Now crime is down and his concerns are more prosaic -- a paucity of midday parking dampens his lunch trade.

This renewal of fortune is causing some residents to wonder how to maintain the character of Silver Spring as real estate values rise and newly arrived chain stores challenge homegrown businesses. Austin Grill, Red Lobster, Strosnider's and Whole Foods are now part of the streetscape.

Del. Ana Sol Gutierrez (D-Montgomery) labels the new Silver Spring "a junior Bethesda," which is a way of saying too many rich people and too many chain stores.

"You could get a taste of everything in Silver Spring," said Debra Wylie, a 17-year resident and a community activist. "That's the kind of flavor that us 'old Silver Spring' people don't want to lose. [Now] it's picked up the tone of every other busy city."

But the Rev. Donell Peterman, a former County Council member and pastor of the Joshua Group Ministries in Silver Spring, said he was wrong to have complained two years ago about looming "Bethesdafication." "I owe Bryant Foulger an apology," he said, referring to one of the principal developers of the new Silver Spring. "I was worried it was going to be one of those plans that pushes away certain classes of people."

Instead, he said, Silver Spring is the hub of diversity in the county.

"It certainly lies within the boundaries of Montgomery County," said Foulger. "But it acts a little bit like north Washington, D.C."

Saving the soul of Silver Spring concerns more than small businesses. At an April forum on Silver Spring's future hosted by County Council member Tom Perez (D-Silver Spring), residents broke into discussion groups to specify what they valued about the area and what they want to maintain as it changes. Diversity -- racial, ethnic and economic -- was the defining word and the quality that many Silver Spring residents seem to cherish above all.

Georgetown University law professor Sheryll Cashin noted in an e-mail that Silver Spring's revitalized downtown, based on her observations, "certainly looks like a multicultural community." In her 2004 book "The Failures of Integration" she writes that "multicultural islands," typically areas with large amounts of affordable housing that have seen an influx of immigration and where no single racial, ethnic or class group dominates, "are a window onto the cultural shift I believe the vast majority of Americans need to embrace if we are to achieve a multiracial, multi-class democracy that truly does offer equality and equal dignity to all persons."

Duncan, who famously vowed to revive Silver Spring "or die trying," is enjoying its success as he campaigns for Maryland's Democratic gubernatorial nomination. He showed up at Kefa Cafe on Saturday to sample its new gelato and shake a few hands.

In a telephone interview last week, Duncan said he wasn't worried about redevelopment chasing out diversity in Silver Spring, noting that the county as a whole is "such a diverse community -- that's not going to change."

Dolores McDonagh, who moved to Silver Spring from Adams Morgan 14 years ago, sat at a table at Kefa Cafe, sounding determined to do her part. "If they're open," she said, referring to Lene Tsegay and her sister Abeba, the sisters who run the place, "I won't go anywhere else." McDonagh has patronized the cafe since it opened nine years ago.

But she added that the county has to invest more money in affordable housing in the area if Silver Spring is to maintain its character. "If we lose economic and racial diversity, Silver Spring will become Bethesda," she said. "Bethesda is good, but we don't need two."

Crime novelist and Silver Spring resident George P. Pelecanos said he checks to see whether Silver Spring Books has the volume he needs before he goes to the just-arrived Borders. He stays true to Vicino Ristorante Italiano on Sligo Avenue, because the proprietor "puts out a better product" than the newcomers.

"People have to make a conscious choice," he said, and they're more likely to do so if they are of a certain age. "The people coming up -- kids, teenagers, people in their twenties -- they're programmed to go to those places," he said, referring to restaurants and stores run by large corporations.

Laura Steinberg, the outgoing board chairman of Impact Silver Spring, a nonprofit group funded in part by county grants, said there is a difference between voicing support for diversity and taking the steps necessary to maintain it.

On one level, she said, people need to think about the repercussions of choosing Starbucks over Kefa Cafe. On another, she added, residents of the new Silver Spring may need to assert more control over what happens next. "Now that we're past the toddler years and we've become more mature, are we up to owning our own future for ourselves?"

Lene Tsegay, one of the owners of Kefa Cafe, waits on a customer as longtime customer Ian Karn, 9, of Silver Spring looks on.