Marie Tsucalas, a resident of Riderwood, a 120-acre gated retirement community in Silver Spring, says, "I feel like I live on a cruise ship without any seasickness."

While all residents are 60 or older, Riderwood is definitely not a rocking-chair community. Programs and activities are mostly resident-generated and resident-run.

Woodworkers expertly create kitchen cabinets for Habitat for Humanity houses. Nonagenarians lob tennis balls over the nets. Nature lovers eagerly await wildlife habitat certification after tweaking the landscape to provide housing and food for birds, small mammals and insects.

Sure, there are the hard-core bridge players who seem anchored to their tables, but there are also Shakespeare aficionados who participate in theatrical readings and resident scientists who lead seminars on astronomy, chemistry and medical research. Budding clowns, dog lovers and history buffs all have found niches.

Tow Moy, an engineer who helped design Metrorail, tends his Chinese squash in one of 167 garden plots available. There's a Helen Club for residents who share the name and a Night Owl club for those who stay up late. More than 100 community college classes are offered on site; for $50 a month, residents can take as many courses as they like.

Riderwood, built by Erickson Retirement Communities LLC beginning in 2000, has 2,200 residents. When it's completed in 2007, there will be room for 3,000. Apartments are designed for independent living, as is the entire community: The idea is to allow people to live on their own as long as possible. Nineteen buildings, including four clubhouses, are connected by glass-walled, climate-controlled, elevated walkways. There's more than a mile of interior corridors, all wide enough for walking side by side or navigating via electric scooters. And, in case health declines, there is a continuing-care facility on site.

To live at Riderwood, residents pay a buy-in fee, then monthly fees. The buy-in charge is refundable should a resident move and are returned to the estate if a resident dies.Units are not sold; rather, there are refundable entrance fees from $84,000 for an efficiency to $423,000 for a two-bedroom, two-bath unit. There are additional refundable charges for units with balconies, patios and bay windows. Monthly fees range from $1,155 to $1,822, with a $571 supplement for a second person in an apartment. The monthly fee includes property taxes, maintenance, landscaping, one meal a day in one of four restaurants, shuttle service, recreational facilities, classes and all utilities except telephone.

All residents have a Silver Spring address, but the complex straddles the Montgomery-Prince George's county line. While services are the same, voting districts are different.

In the large common areas, conversations are vibrant, full of humor and focused more on what activities people are pursuing than the stereotypical recounting of the day's woes. The most frequent overheard comment is, "I have to check my calendar."

Leaving houses and careers behind, many residents plow full throttle into new interests. Jim Feldman, a retired Foreign Service officer, joined an animated group as they put the finishing touches on a teleplay they were shooting in Riderwood's well-equipped TV studio. Doris Terry, a former pitcher for the Racine Belles in Wisconsin, one of the women's baseball teams immortalized in the film "A League of Their Own," lined up interviews for her program called "I Wanna Be a . . .," in which guests share their goals for the future.

Talents displayed by residents are "mind-boggling, particularly among the craft people," said Milton Feldman, an original resident. "They are artists -- and I mean artists, not someone just spreading paint on canvas."

Esko Hallila, a former Veterans Administration electrical engineer who immigrated from Finland in 1927, enjoys greeting residents in Finnish, Korean or Japanese. Since moving to Riderwood, he said, "I meet so many people from different countries," giving him ample opportunity to hone his language skills.

People who have lived all over the world have stories to tell and love to tell them. It's that readiness to chat that makes newcomers feel welcome, residents say, easing what is, for some, a difficult transition from private homes. Some come to Riderwood after losing a spouse in order to be closer to grown children living nearby. Others are long-married couples tired of tending to home repairs and yard work. Eighty percent of residents come from surrounding areas, and many of those say they chose Riderwood after visiting friends who live there.

Open spaces around the buildings are landscaped with well-placed benches, gardens, ponds and a gazebo. Resident Anne Blackburn, chief organizer of the Weed Warriors, a group that attacks plants they refer to as "vicious invasives," raves about the community's environmental efforts, including introducing rescued red slider turtles to the ponds, promoting growth of native plants and attempting to attract wood ducks to boxes made on site.

Residents mentor students, 14 and older, who work in the community's four restaurants and in various offices, learning responsibility and job skills. Many of the young people qualify for $1,000 scholarships for each of four years as full-time students in any college or trade school.

"Been there" career guidance and encouragement from seniors gives students a perspective not found in textbooks. Ferddy Calderon, 19, who has worked in dining services for five years, expressed gratitude for how residents such as George Bain, a former World Bank economist and university professor, and George Sharp, a retired physician, helped chart his path.

Calderon, originally from Guatemala, attends the University of Maryland and plans to become a neurosurgeon. "My relationship with residents has changed from employee and customer to mutual friendship," he said.

Bain and his wife, Mildred, an artist, moved to Riderwood six months ago. "I always ask the kids what they are doing," he said. He encourages students to take tough courses, and he enjoys guiding them in finding resources for their studies.

Bethlehem Beru, 18, now studying broadcast journalism in college, wrote in Riderwood's scholarship yearbook: "I have been fortunate enough to form bonds with retired pilots, war veterans, lawyers, doctors, and just all around good people. To think of their past and what they have been through in their lifetime made me appreciate them more. No longer were they just residents, they were real people who achieved amazing accomplishments during their careers."

Riderwood, a Silver Spring gated retirement community, has a 120-acre campus-like setting with paths and ponds.The Weed Warriors at work: Anne Blackburn, center, guides volunteers in digging up garlic mustard before it goes to seed so that the native plants can flourish. Their efforts have placed Riderwood, in Silver Spring, on the road to being named a wildlife habitat by the Wildlife Habitat Council, a nonprofit nationwide environmental group.