geecu

var vimBinding = document.createElement('script');
vimBinding.setAttribute('src','https://raw.github.com/marijnh/CodeMirror/master/keymap/vim.js');

var mirrors = document.querySelectorAll('.CodeMirror');
 
// browser support for onload may be iffy ...
vimBinding.onload = function () {
  Array.prototype.forEach.call(mirrors, function (instance){
   instance.CodeMirror.setOption('keyMap','vim');
  });