A Decentralized Middleware for Groupware Applications

Many advances have been done to allow groups of people to work together and collaborate in the Internet. Most of these advances rely on a single server or other centralized communication topologies. However, pure decentralized approaches can bring many benefits to groupware applications, such as scalability, robustness, availability and easy deployment. In this paper, a decentralized middleware for groupware applications is presented, which enables people to join and cooperate in groups in a robust and easy deployable way, without relying on a central server or requiring any other special infrastructure. Two applications, one for synchronous groupware and other for asynchronous collaboration are shown as examples of successful experiences. This groupware middleware is based on a binary tree as overlay structure, which implements all groupware communication functionality, including membership management and packet forwarding, at application level, making it suitable for the Internet. Comparisons with other approaches in aspects such as throughput, protocol overhead, resource utilization and group bandwidth, shows that this middleware is a scalable and robust communication scheme to synchronous or asynchronous groups in the Internet.