Today marked the end of Jane Jacobs' life, but not of her work. Jacobs' pioneering work in urban planning changed the way we think about cities -- and by redefining our ideas about how cities work as communities, she set the stage for the best thinking about online community today.

I grew up in a community that was profoundly shaped by Jacobs' ideas. As recent American immigrants to Toronto, my parents were active in the "Stop Spadina" campaign against a planned expressway -- a campaign in which Jacobs herself played a major role. By the time I was born, they'd moved to a working class neighbourhood of Toronto that was scheduled for old-school urban renewal; my folks were part of a local movement that successfully fought for community-centered preservation and development. Both my immediate neighbourhood and my parents' social/political circles were defined by the beliefs that cities belonged to their residents, that the best community decisions came from communities themselves, and that all politics were fundamentally local -- beliefs that Jacobs helped to define and expound.

Jacobs' death reminds me how much my own work in online community, and the work of Internet community-builders in general, owes to that earlier generation who reclaimed urban centres as living communities. The most important principles of online community building and online dialogue grow out of the experiences of urban community planners and participation planners: Communities are about people, not structures. Healthy communities are owned and shaped by their members, not by some team of expert planners. Communities thrive on activity and diversity. And if many of the most influential experiments in online community are those that tie online communities to real-world towns and cities -- projects like Die Digitale Stadt, MeetUp or even craigslist -- they also owe a debt to Jacobs for helping to keep those real-world communities vital.

Jacobs herself was intrigued by the Internet's capacity to support meaningful community. In a 2002 interview, she talked about online interaction as a way for people to explore different models of community, and for modeling real-world communities:

We are emerging from this linear cause-and-effect way of seeing the world into a way that has really been led by the ecologists, into a Web world, beginning to understand relationships in quite a different way. And it is affecting everything. And no end of people have grasped this and are seeing the world differently and analyzing things differently and seeing possibilities differently--basically in a very hopeful way.

These still-early days of online community-building amount to explorations of the potential that Jacobs identified: the potential for supporting real human relationships with virtual ecosystems. And in a wonderful tribute to Jacobs' continued influence, many of these experiments feed back into twenty-first century cities by providing new tools for supporting urban sustainability. I've bookmarked a few of my favorite examples on del.icio.us with the tag JaneJacobsArchive; I hope others will contribute their own examples of how the Internet can support the kinds of cities that Jacobs so eloquently advocated.