R: obtaining a GUI
http://www.psychol.cam.ac.uk/statistics/R/getting_gui.html

R is extendable by packages. They are very easy to install. Several provide graphical user interfaces (GUIs) to make working with R simpler. One such is the R Commander. To run it, proceed as follows.

  1. Run R (see the installation tips).
  2. On the menus, choose Packages > Install Packages. Or, from the command line:
  3. install.packages()
    
  4. Choose a CRAN mirror that is geographically near to you.
  5. Browse through the list of packages and select Rcmdr. Everything is then downloaded and installed automatically.
  6. Type library(Rcmdr) at the R prompt. (The first time you do this, Rcmdr will tell you that packages are missing, and ask you whether it should install the missing packages; answer Yes, and accept installation from CRAN.) Once Rcmdr starts, you will see something like the picture below. You may need to rearrange your R and R Commander windows until you can see both.
R Commander at startup
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