The original repos still live, although it hasn't been updated since 2009. This repos serves only to allow monokai.vim to be installed using modern plugin managers for vim.
There's also a vim.org Script page for this colorscheme.
Add to your .vimrc:
Don't forget to
:PluginInstall after editing your config files.
Fetch it over the net and store it locally in your
$ cd ~/.vim/colors $ curl -G https://raw.githubusercontent.com/lsdr/monokai/master/colors/monokai.vim -o monokai.vim