There’s a myriad of AJAX frameworks out there to streamline the development of interactive sites. While methods of implementation vary and the functionality toolkits offer can vary dramatically. All toolkits fundamentally provide you with certain key features.
Basic Features

• Simplified AJAX calls. All frameworks streamline the way in which you process POST and GET requests by abstracting away the cross browser descrepancies.
• Improved DOM Access. All frameworks improve interactions with the DOM through performance benefits and improved API calls.
• Object Orientation / Elements. All frameworks provide a level of object oriented abstraction to simplify and structure coding as well as some level of abstraction for DOM nodes.
• JSON Support. Most if not all frameworks provide strong support for the JSON data interchange standard.

Advanced Features
There are also some advanced features common to most if not all frameworks.

• Drag & Drop. Most frameworks provide tools for manipulating elements via drag & drop.
• Animation. Many frameworks provide animation tools to enhance the interface. These can vary dramatically between toolkits in performance & available effects, however.
• Event Handling. Since the default javascript event model can be slow and buggy at times. Most frameworks abstract away the default event system with a new slots & sockets approach.

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