3 Cesare Pautasso 2009 International Conference on Software Composition 2009 Zurich, Switzerland Springer 5634 142–159 LNCS July REST,Service Composition,DoodleMap The REST architectural style is emerging as an alternative technology platform for the realization of service-oriented architectures. In this paper, we apply the notion of composition to RESTful services and derive a set of language features that are required by composition languages for RESTful services: dynamic late binding, dynamic typing, content-type negotiation, state inspection, and compliance with the uniform interface principle. To show how such requirements can be satisfied by an existing composition language, we include a case-study using the JOpera visual composition language. In it, we present how to build a composite application (DoodleMap) out of some well-known, public and currently existing RESTful service APIs.