planetlab is an experimental global network of computers designed to let researchers develop and test powerful new types of software that operate across multiple computers, treating the global network as a single, widely distributed computer. a new class of geographically distributed network services is emerging, and the most effective way to design, evaluate, and deploy these services is through an overlay-based testbed. this approach allows both researchers developing new services and users wanting to use them. four design principles are suggested for such testbeds: services should run continuously and access a slice of the overlay's resources; resource control should be distributed; overlay management services should be unbundled and run in their own slices; and APIs should promote application development. this talk describes this vision and reports on the status and plan for realizing it in planetlab. scott karlin is a research associate in the department of computer science at princeton university, where he completed his ph.d. last fall. before returning to graduate school, he worked for trw space and defense, the aerospace corporation, and nicholas applegate capital management. he holds an m.s. in computer science from loyola marymount university and a b.s. in electrical engineering from the california institute of technology. the meeting is on thursday, november 20, 2003, at 8:00 pm, with refreshments at 7:30 pm. the location is the sarnoff corporation, routes 1 and 571, princeton, nj. information is available at http://www.acm.org/chapters/princetonacm. all meetings are open to the public, including students and their parents. a pre-meeting dinner with the speaker is held at 6:00 pm at ruby tuesday's restaurant on us 1. please contact princetonacm@acm.org in advance if you plan to attend the dinner.planetlab is an experimental global network of computers designed to let researchers develop and test powerful new types of software that operate across multiple computers, treating the global network as a single, widely distributed computer. a new class of geographically distributed network services is emerging, and the most effective way to design, evaluate, and deploy these services is through an overlay-based testbed. this approach allows both researchers developing new services and users wanting to use them. four design principles are suggested for such testbeds: services should run continuously and access a slice of the overlay's resources; resource control should be distributed; overlay management services should be unbundled and run in their own slices; and APIs should promote application development. this talk describes this vision and reports on the status and plan for realizing it in planetlab. scott karlin is a research associate in the department of computer science at princeton university, where he completed his ph.d. last fall. before returning to graduate school, he worked for trw space and defense, the aerospace corporation, and nicholas applegate capital management. he holds an m.s. in computer science from loyola marymount university and a b.s. in electrical engineering from the california institute of technology. the meeting is on thursday, november 20, 2003, at 8:00 pm, with refreshments at 7:30 pm. the location is the sarnoff corporation, routes 1 and 571, princeton, nj. information is available at http://www.acm.org/chapters/princetonacm. all meetings are open to the public, including students and their parents. a pre-meeting dinner with the speaker is held at 6:00 pm at ruby tuesday's restaurant on us 1. please contact princetonacm@acm.org in advance if you plan to attend the dinner.