Data mining focuses on extracting useful information from large volumes of data, and thus has been the center of much attention in recent years. Building scalable, extensible,and easy-to-use data mining systems,however,has proved to be difficult. In response, the authors developed Anteater, a service-oriented architecture for data mining that relies on Web services to achieve extensibility and interoperability, offers simple abstractions for users, and supports computationally intensive processing on large amounts of data through massive parallelism.