Graphic User Interfaces
R is a command line driven program. The user enters commands at the prompt ( > by default ) and each command is executed one at a time.
There have been a number of attempts to create a more graphical interface, ranging from code editors that interact with R, to full-blown GUIs that present the user with menus and dialog boxes.
RStudio is my favorite example of a code editor that interfaces with R for Windows, MacOS X, and Linux platforms.R Commander, which can also run under Windows, Linux, and MacOS X (see the documentation for technical requirements).
Both of these programs can make R a lot easier to use.
This interactive course gives an overview of installing and working with RStudio.