Building Custom GUIs for R

Are there any tools currently available that enable us build GUIs??? (MATLAB
has a GUI builder that enables the users build custom GUIs).

Another option nobody has mentioned yet is to make it a web-based
system, and generate your dialogs using HTML FORM elements. R comes
with a basic web server engine now so it might be possible to make it
all self-contained.

Can we make a exe of such GUI (with the R code) and let people use it
without having to install R???

That's another FFAQ to which the answer is usually 'no', although you
can of course distribute R alongside your application (by closely
following the terms of the R license agreement) and say in your
install notes "first install R by running setupR.exe" or whatever.

Barry