Many organizations which are moving to a service-oriented architecture (SOA) have a significant legacy infrastructure running on IBM’s System z. Several options exist for service enablement of these applications. This article describes why you might want to consider System z as the foundational platform environment for your SOA environment. You see why using WebSphere as the core for your infrastructure on System z enables you to develop services which maximize reuse. You see an environment which supports services and which enables scalability, availability, and performance required for the enterprise. You also see how System z fits into a heterogeneous SOA environment. This article is intended for architects and developers building an SOA infrastructure who are deciding on a target platform. Readers should have a basic knowledge of both Service Oriented Architecture and IBM System z.