This tutorial guide for anyone wanting to start building Service-Oriented Architecture applications using powerful, free tools explains in detail how to build and deploy them by creating Web Services with PHP, combining them into SOAs with WS-BPEL using free ActiveBPEL Designer, and deploying composite WS-BPEL-based orchestrations to the open-source ActiveBPEL engine. Unlike many books on SOA, it is not focused on architecture, but discusses practical aspects of SOA and WS-BPEL development with many examples, showing you how to apply architecture in practice. In SOA, Web Services are part of a business process determining the logical order of Service Activities - logical units of work performed by one or more services. Today the most popular tool for organizing service activities into business processes is Web Services Business Process Execution Language (WS-BPEL). A graphical WS-BPEL tool like ActiveBPEL Designer can significantly simplify defining a business process with WS-BPEL.