Good GUI for R suitable for a beginner wanting to learn  programming in R? Is there any GUI for R that makes it easier for a beginner to start learning and programming in that language?
 A: At least on linux, RKWard offers the best functionality. The new RStudio appears quite promising as well.
A: Personally ESS, but as stated above i have found Rcmdr very easy to use. 
A: I would second @Shane's recommendation for Deducer, and would also recommend the R Commander by John Fox.  The CRAN package is here.  It's called the R "Commander" because it returns the R commands associated with the point-and-click menu selections, which can be saved and run later from the command prompt.  
In this way, if you don't know how to do something then you can find it in the menus and get an immediate response for the proper way to do something with R code. It looks like Deducer operates similarly, though I haven't played with Deducer for a while.
The base R Commander is designed for beginner-minded tasks, but there are plugins available for some more sophisticated analyses (Deducer has plugins, too). Bear in mind, however, that no GUI can do everything, and at some point the user will need to wean him/herself from pointing-and-clicking.  Some people (myself included) think that is a good thing.
A: I used Rattle to both learn how to use R and for quick and dirty data mining tasks.
A: GUI  != Programming
Asking which GUI will help you learn programming is like asking which grocery store will help you learn how to hunt for your own food.  Using a GUI is not a way to learn programming.
The power of R is that it's not GUI driven, it uses scripts which fundamentally allow for more more reproducible results.
GUIs to demonstrate specific topics / Brief backpedaling
That having been said, I do think it's useful to use a GUI to demonstrate a single specific topic.

*

*The latticist package is awesome for creating lattice graphs and learning lattice syntax.

*The PBSmodelling package has some wonderful examples of GUIs that allow you to run specific models, such as MCMV models.

*The TeachingDemos package is also seems to have some good demos of specific topics.

Roll your own GUI
The PBSmodelling package also has tools that allow you to make your own GUIs.  This includes some amazing tools for project organization and documentation.  Thank you Pacific Biological Station!
Also, by using Rook and Apache you can also make powerful web-based GUI applications.
Making your own GUI is not appropriate for beginners or the direct answer to your question.  However, if you're an advanced user then you might want to consider making a GUI to demonstrate a particular topic.
The installed "R" is a GUI (technically)
It's worth noting that the installed version of R is a shortcut to Rgui.exe.
I know that you're asking for a GUI that let's you access all of the base functionality of R by pointing and clicking, not a glorified wrapper for the command line.
However, it's important to realize that a GUI wrapper for the command line is a GUI, and it's a valid answer to your question.  The command line is the only way that you can get access to the rapidly evolving functionality of the power of R and the freshly packages authored daily.
So...
Again, the best GUI is R Studio
The best interface for R is definitely R Studio.
For some people the StatET / Eclipse interface is important for it's powerful features, but R Studio is rapidly overtaking those features and adding new ones.
Revolution R (the commercial version) also has a GUI, but it's not so great unless you are deeply passionate about the design of MS Visual Studio.  However, you can access Revolution's build of R though R Studio or Eclipse, so that's a pretty neat trick too.
A: This has been answered several times on StackOverflow.  The top selections on there seem to consistently be Eclipse with StatET or Emacs with ESS.
I wouldn't say that there are any good gui's to make it easier to learn the language.  The closest thing would be deducer from Ian Fellows.  But there are plenty of other resources (books, papers, blogs, packages, etc.) available for learning.
A: I used JGR for a short while, until it became apparent it would quickly consume all the memory on my system. I have not used it since, and recommend you do not use it.
A: I recommend Tinn-R (Which is the acronym for Tinn is not Notepad)
A: Despite all of the good recommendations, I've not found anything radically better than the default Mac GUI. R-Studio shows promise, but it's not currently that much more customizable or featureful than R and, say, BBEdit to edit.
A: I would recommend having a look at AirXcell. It's an online (Web 2.0) calculation software based on R which provides a quite usable R GUI with a command line interface (The R console) a code editor, and various other things (data frame editor, etc.), all online from within the web browser. 
See Use AirXcell as an online R console.
A: I think that the command line is the best interface, and especially for the beginners. The sooner you'll start with console, the sooner you'll find out that this is the fastest, the most comfortable and what's most important the only fully non-limiting way of using R.
A: You can also try the brand-new RStudio.  Reasonably full-featured IDE with easy set-up.  I played with it yesterday and it seems nice.
Update
I now like RStudio even more.  They actively implement feature requests, and it shows in the little things getting better and better.  It also includes Git support (including remote syncing so Github integration is seamless).
A bunch of big names just joined so hopefully things will continue getting even better.
Update again
And indeed things have only gotten better, in rapid fashion.  Package build-check cycles are now point-and-click, and the little stuff continues to improve as well. It now comes with an integrated debugging environment, too.
A: Having worked with the  


*

*(Base) R  

*RStudio  

*Revolution R Enterprise   


in Windows environment, I strongly suggest "Revolution R Enterprise".
I accept that its installing takes little longer (it is 600-700MB) if compared with BaseR and RStudio, but anyway, the Object Browser of Revo R, the easiness of package installation procedure, management of variables, etc. etc. there are many things that - according to me - makes Revo R the best one (acc. to  me).
That said, Revo R being purchased by Microsoft is - to me- one of its drawbacks since MS is eventually profit-oriented firm and may change its free nature sooner or later.
A: Quadstat is a free browser-based front-end to R and also an open-source statistical web application framework. After submitting a computing query, the user is presented with output from the request and also the R commands used. Prior to submission, the R help file is clearly displayed so that the user may understand some of the internals of R. I am the project maintainer and hope you find the software useful.
https://quadstat.com
https://www.drupal.org/project/quadstat
A: If you don't want to code R, but want graphical user interface like SPSS, there is a new cloud based software, Number Analytics (). It is based on cloud so you don't need to install the program. It is freemium model starting free. It is for beginners who don't have much knowledge about statistics. The biggest selling point is that it does interpret the statistical results. Color table, and built-in graphs also helps. 
