REST, the REpresentational State Transfer, is the architectural style underlying the HTTP protocol. In the last couple of years, REST has emerged as a compelling and simpler alternative to SOAP/WSDL-based distributed architectures. In this session, Arjen will explain what REST is, how it can be used to build Web Services, and where it makes sense to use. We will start by giving an overview of REST: where did it come from, how does it work, and how can it be used to build a distributed architecture? Using illustrative examples, we will try to find an answer to these questions. Next, we look at some of the current frameworks and tools which can be used to build web services. We will look at Spring-MVC and JSR-311 (also known as JAXRS) on the server-side, and also investigate client-side options, such as the plain HttpURLConnection, and the more mature Commons HttpClient.