Middleware eases the development of distributed applications. Expansion in the enterprise world entails integration of heterogeneous products, and there is a demand for a balance between performance, interoperability and security in the distributed applications. Windows Communication Foundation (WCF) offers a technology to build service-oriented, secure, reliable and interoperable distributed applications. The current literature contains few studies comparing the performance of WCF with other technologies, but it does not address the performance of WCF in a cross-technology communication. This book experimentally evaluates the performance of WCF in unsecure and secure variants. It evaluates the performance in on-machine and cross-machine communication, and it addresses the performance of WCF''s interoperability with ASMX and Java clients. The experiments are conducted using client and service applications in a laboratory setting. We have measured the performance in terms of throughput, response time, processor and memory utilization during the experiments.The book should help the research/industry practitioners to understand the efficient technology and promote the research flow.