RStudio is a visual interface for the R statistics program. Swarthmore runs an RStudio Server Pro instance at http://rstudio.swarthmore.edu. You can log into the server using your Swarthmore username and password, but first need to request an account.
Troubleshooting
Terminal or Shell Not Working
If there are problems with opening up a new Terminal or Shell, try going to Tools → Global Options → Terminal. Then uncheck "Connect with Websockets".