This is used for custom Ajax requests made from GridBuddy grids.
The contentType must be text/javascript since the Ajax calls use JSONP.
Type: Visualforce
<apex:page controller="GridAjaxDelegator" action="{!processRequest}" contentType="text/javascript; charset=utf-8" showHeader="false" standardStylesheets="false" sidebar="false">
handleJsonpCallback({!jsonResponse})
</apex:page>