In this paper, we present the mechanisms needed for Byzantine fault tolerant coordination of Web services atomic transactions. The mechanisms have been incorporated into an open-source framework implementing the standard Web services atomic transactions specification. The core services of the framework, namely, the activation service, the registration service, the completion service, and the distributed commit service, are replicated and protected with our Byzantine fault tolerance mechanisms. Such a framework can be useful for many transactional Web services that require high degree of security and dependability.