ESS is a package that integrates various statistical software with Emacs. S, R (a free implementation of S), Stata, and SAS modes are all supported by ESS, making it possible to hook writing and programming in Emacs right into your stats. It’s pretty slick.
Consider using the prefix “ESS” for new ESS-related pages. – PaulJohnson
(setq ess-eval-visibly nil) ; ESS will not print the evaluated comands, also speeds up the evaluation (setq ess-ask-for-ess-directory nil) ;if you don't want to be prompted each time you start an interactive R session
S-<return>’ can launch R and send commands to R (by FelipeCsaszar)