But there's a twist. No matter whether users choose to be greedy, benevolent or something in between, they'll still end up contributing processing power to both for-profit and nonprofit clients. Minar designed the system so that even libertarian Ayn Rand fans who click the "maximize payment" option and utterly disdain charity will still end up donating at least some time and effort to helping scientists find a better flu vaccine. And vice versa.

"It's a commercial and socially conscious ideal," says Popular Power's chief technical officer, who founded the San Francisco company a year ago with his college buddy Marc Hedlund. For both business and ethical reasons, "It's the right thing to do."

On the one hand, he says, "We're scavenging these resources, so why shouldn't we give back to the public good?" And on the other, "Popular Power is a business, not a charity," so why should do-gooders completely avoid helping the company's corporate clients?

Cash and community, profits and dreams of a more perfect electronic union: Welcome to the peer-to-peer (P2P) scene, circa late 2000. Sure, the essential tenet of peer-to-peer -- the idea that computers can work together as both servers and clients -- started kicking around 20 or 30 years ago. And yes, "P2P" only attained buzzword status because Napster convinced millions to download its software and trade music with each other. But the developers following in those file-swappers' footsteps also see themselves as pioneers. They want to mine P2P for more than just gold or their MP3s. They are also aiming for a better world.

Whether it's Uprizer growing out of the free-speech-inspired Freenet, or Mojo Nation's attempt to build a libertarian utopia or Parabon's plan to compute against cancer, "There is a real sense of idealism surrounding peer-to-peer," says Ian Clarke, creator of Freenet.

Hackers, engineers and even venture capitalists now talk with giddy exuberance about how peer-to-peer will let average, everyday users "reclaim the Internet" and encourage them to join together in massive communities to code, sing and speak their minds without fear. Not only will they compete with giants like Yahoo for traffic, but maybe, just maybe, they'll use this new "Inter-internet" to make the world a healthier place.

Achieving their starry-eyed goals won't be easy. At least one critic, Andreas Stavropoulos, a director of the venture capital firm Draper Fisher Jurvetson, says that peer-to-peer prophets like Clarke and Minar are living in a dream world. "They have simplistic assumptions about what it takes to close real accounts, to drive real revenues," he says. "They suffer from idealism," and thus, they fail to understand that drawing users and customers requires more than just passion. "You can't just walk in and get [people or companies] to run untested peer-to-peer platforms that are expensive and may or may not offer great value," he says. "It's unrealistic; it won't happen."

Still, Minar and his ilk continue to toil away, unfazed. They're convinced that science and society will soon crave more than just Napster and that the work they're presently doing -- improving interfaces, creating incentive schemes, testing stability -- will draw the crowds they need to survive, thrive and make a difference.

"Peer-to-peer is growing up," says Gene Kan, a developer of Gnutella for Unix-based computers.

"There's idealism running throughout peer-to-peer," adds Tim O'Reilly, the computer book publisher who also sits on Popular Power's board of directors. "And that will continue to be the case. It's a real revolution."

The Free Software Project
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