Installing R and X11, MacOS Users only
1. Make sure that your MacOS is up-to-date by running Software Update from the Apple menu in thetop-left.
2. You will go to CRAN and download R, as the Windows users did. Obviously choose the MacOS versionrather than the Windows version.
3. The tricky part is that Mac users will need to install the X11 windowing system, as R Commander usesthat rather than the default Mac Quartz. Go to http://www.xquartz.org/ and download the disk-imageﬁle (.dmg) found there.
4. Open that ﬁle by double-clicking and then double-click on XQuartz.pkg. Install, choosing defaults,and then reboot your computer. You then should be able to follow the upcoming slides to install RCommander.

Here's something a student emailed me regarding installing R Commander for a Mac. Hope this helps.

Finally, the thing that took to FOREVER to figure out:

When you enter "require(Rcmdr)" into the R-Console using syntax commands, make sure you have X11 open on your computer. The R-Console will show an error message if X11 application is not open and running in the background. Also, the X11 and R-Console cannot be minimized (or in the dock of the Mac) or else it will not let you import data or run data analyses. Rcmdr will be frozen and unresponsive if both X11 and the R-Console are not both open (and not minimized) on the Mac dock.