When I first started learning R, I used R Commander as my GUI since it worked with all my operating systems and was relatively easy to setup and use. After a few months, I came to appreciate the simplicity of the RGui that is standard on R installation. Now, I am ready for something more advanced and have decided to try ESS (Emacs Speaks Statistics). Since I do not have any prior experience with Emacs and have not invested any time creating configuration settings and learning keyboard shortcuts, my main goal was to get a very Mac friendly Emacs version that just worked. OS X does come with Emacs installed but I didn’t want to go through the hassle of setting up ESS with the existing EMacs. I decided to use Aquamacs because it looks and behaves the most like a modern OS X application and has ESS enabled when installed. Emacs is available through the terminal but setting up and using ESS without menus does not provide an easier working environment than the RGUI or R Commander.
Emacs uses what are called meta commands since it originated before toolbars. To execute a meta command, type <Ctrl> u, <alt> x and the actual command. On Aquamacs, the right option key is set up to be the meta key so you can simply press <option> x before the actual command. You can also use the <esc> key as the meta key. To start R, press <option> x R <return> or <esc> x R <return>. You can also open an existing R script and click the R icon to start R. To customize ESS, select Customize Aquamacs -> Customize Group… from the Options menu and type ess at the prompt. You can also click the settings icon only after you have opened an R script. I like to have ESS start from the the same directory every time so I add my directory to the “ESS Directory” option and turn off the “ESS Ask for ESS Directory” option. Make sure to “Save for future sessions” before closing the buffer. I had already deleted R32 so I know that Emacs will default to R64 but I’m not sure how to work with both versions.
Update: I have now switched to RStudio since it is free, cross platform compatible, and simple to setup. I highly recommend it to any R user.