Emacs is a great front-end for most of the command line tools. Although R-Studio is pretty good, I think Emacs/ESS is better. I’ve always used Emacs/ESS to run R, since 2007 on Ubuntu, Windows, and my MacBook Pro. It gives me the same experiences across all platforms. I love the way Emacs formatting source codes, and literate programming with Roxygen supported. Unfortunately, ESS does not suport displaying plots in Emacs buffer, which has been supported by imaxima.