Title: Exposing R as Java-based web services Authors: Nianhua Li, Martin Morgan, Seth Falcon, Robert Gentleman Abstract: Web services are one way to integrate the distributed and heterogenous data and analytic resources required by modern statistical analyses. Here we introduce RWebServices, a package that exposes R objects and functionality as web services. The approach uses strongly typed R functions (using the TypeInfo package), the S4 class system, and SJava to facilitate automatic conversion between R and Java objects and methods, and to provide an SJava-based interface to R functions. The Java objects and methods created by RWebServices are then exposed using well-developed Java-based web services infrastructure. The flexibility of this approach is illustrated by a related effort, to integrate parts of the Bioconductor project into the Cancer Biomedical Informatics Grid.