Add jQuery, DOJO or YUI libraries to your project for advanced content assist. The editor has inbuilt support for the prototype framework's OOP constructs.
Here we can see the content assist and documentation for the insertBefore function
The ScriptDoc support exists here too, providing methods specific to the return type of the inArray method
Support for the XMLHttpRequest object
Support for the $ closure
The editor understands the Class.create method
Support for subclasses