Description:

Zend_Json provides convenience methods for serializing native PHP to
JSON and decoding JSON to native PHP.

JSON, JavaScript Object Notation, can be used for data interchange
between JavaScript and other languages. Since JSON can be directly
evaluated by JavaScript, it is a more efficient and lightweight format
than XML for exchanging data with JavaScript clients.

In addition, Zend_Json provides a useful way to convert any arbitrary
XML formatted string into a JSON formatted string. This built-in
feature will enable PHP developers to transform the enterprise data
encoded in XML format into JSON format before sending it to
browser-based Ajax client applications. It provides an easy way to do
dynamic data conversion on the server-side code thereby avoiding
unnecessary XML parsing in the browser-side applications. It offers a
nice utility function that results in easier application-specific data
processing techniques.