Managing distributed collaboration in a peer-to-peer network

Shared mutable information objects called u-forms provide an attractive foundation on which to build collaborative systems As we scale up such systems from small fully-connected workgroups to large, highly distributed, and partially disconnected groups, we have found that peer-to-peer technology and optimistic replication strategies provide a cost-effective mechanism for maintaining good performance Unfortunately, such systems present well-known coordination and consistency problems This paper discusses strategies for addressing those difficulties at different levels of the system design, focusing on providing solutions in the information architecture rather than at the infrastructure layer Addressing problems at this higher layer allows greater freedom in design, and simplifies moving from one infrastructural base to another as technology evolves Our primary strategy is to enable robust decentralized and asynchronous collaboration while designing architectures that do not rely on two users writing to the same u-form at the same time in different venues Techniques are provided for simple messaging, collaborative maintenance of collections, indexing supporting rich query, and stand-off annotation and elaboration of third-party datasets We outline the application of these techniques in a working collaborative system.