Commodity machine clusters can provide a scalable and highly available platform to deploy Web application and Web services. The networking software required for such clusters, however, is often custom to the specific application and can be daunting to write and test. This article shares how JavaGroups, an open source distributed systems toolkit, can help by providing ready-to-deploy, high-level features such as: group membership management, multicast and unicast message-based group communications, state transfer protocol, functional distributed data structure, and a library of reusable, frequently used communication coding patterns.