Some APIs may have changed since this version was released. If using this version, find out about our version support<.
All the aspects of the API that were added, or had a new signature added, in the corresponding version of jQuery.
jQuery 1.5 also includes a large rewrite of the Ajax module, which has a number of extensibility improvements. You can find out more about those improvements in the Extending Ajax documentation.
Additionally, jQuery 1.5 includes a new Deferred callback management system you can learn more about in the Deferred Object documentation.
A factory function that returns a chainable utility object with methods to register multiple callbacks into callback queues, invoke callback queues, and relay the success or failure state of any synchronous or asynchronous function.