What is Rook? Rook is a web server interface for R, written by Jeffrey Horner, the author of rApache and brew. But unlike other web frameworks for R, such as brew, R.rsp (which I have used in the past1), Rserve, gWidgetWWWW or sumo (which I haven’t used yet) Rook appears incredible lightweight. Rook doesn’t need any configuration. It is an R package, which works out of the box with the R HTTP server (R ≥ 2.