AngularJS Example:

HTML

<link rel="stylesheet" href="http://twitter.github.com/bootstrap/assets/css/bootstrap.css">
  <div ng-app="myApp">
    
    <div ng-controller="myCtrl"></div>
      <div ng-controller="myCtrl2">{{value}}</div>
    </div>

CSS

.done-true {
  text-decoration: line-through;
  color: grey;
}

JavaScript

angular.module('myApp', []).controller('myCtrl', function($scope, $rootScope) {
  var a = //something in the scope
  //put it in the root scope
  $rootScope.test = "TEST";
});

angular.module('myApp').controller('myCtrl2', function($scope, $rootScope) {
  var b = //get var a from root scope somehow
  //use var b

$scope.value = $rootScope.test;
alert($scope.value);
});