I have to develop a web interface allowing the user to enter some inputs that will be passed to an Rscript as parameters and return the result to the user.
I have some questions for someone who have done a similar web interface:
R has its own web server, so you could do the whole thing within R. Then there's no need to bother with choosing a framework, or getting them to talk to each other and so on - just use an R framework:
http://cran.r-project.org/web/packages/Rook/index.html
If you don't like that for performance or other reasons, pretty much any framework will talk to R one way or another, so use what you are familiar with. I'd use Django and either call R via Rpy2 or run an Rserve process, but if you can program in PHP or Java then use a framework based on those languages. If you can't program in anything but R then either learn Python or use Rook.