This is the development code of Vim-R-plugin. You may want to adjust Vim's runtimepath in your ~/.vimrc as in the example below:
Stable versions are released at http://www.vim.org/scripts/script.php?script_id=2628
Please, read the file doc/r-plugin.txt for usage details.
If you decide to use this version, you will also need the development version of vimcom: https://github.com/jalvesaq/VimCom