This is a minimalistic webserver written in pure R.
In order to start it:

$ R CMD BATCH webserver.R

the webserver then listens on port 8088 and evaluates the path.
e.g.

curl "http://localhost:8088/paste(Sys.info(),collapse='')"

returns a page with the system info of R.
Be careful, because you open up a security hole. Calls with the system function can execute any bash command on the server.