ApectJ's Eclipse Home "PARC has decided to transfer AspectJ to an openly-developed eclipse.org project. This project will include documentation, web site, mailing lists, bug database, and sources for the AspectJ compiler (the primary tool produced by the project)." Just another part of the growing Eclipse ecosystem.
This follows the Koi Project: "The goal of the Koi project is to develop an infrastructure that can be used to create collaborative features. The addition of specific collaborate features to the Eclipse Workbench are beyond the current scope of the project. However, as a test of the infrastructure, we have created a set of sample collaborative functions that support activities such as messaging, metadata storage, and a shared calendar. These are available as part of the Koi download."
They're using a client/server architecture because "A server-based architecture provides a centralized place to store any collaborative metadata. It also permits expensive computations to be performed without impact on the responsiveness of client machines." most peer-to-peer systems exist to extend both computation and storage capacity of client/server systems. Although they do say, "Thus using Koi, there is the potential for every “client” to also be a “server”. This could form the basis of a Koi peer-to-peer architecture. We think this could be an interesting application of the Koi infrastructure and encourage experimentation in this regard."