The rApache project provides a complete R web application development and deployment environment, however it can be difficult to develop such an application in a server environment. The upcoming release of R 2.13 will provide basic functionality for developing R web applications on the desktop via the internal HTTP server (Rhttpd). Unfortunately rApache and Rhttpd differ in their programming interface. Enter Rack, a web server interface for R. In a nutshell, R users write their web applications using the Rack interface specification, and web servers conform their interface to Rack. We have written an R package (named Rack) that provides the interface spec and implementation for rApache and Rhttpd. With rack, it is feasible that R users can develop web applications on their own desktop R instances and then deploy to a faster, more scalable web server environment.