Cascading Style Sheets and XHTML for layout.
The DOM for manipulation of the layout and interactivity.
XML and XSLT for the exchange and manipulation of data.
XMLHttpRequest for asynchronous communication with the server after the page has loaded.
Although the author of the article played no part in inventing any of these things, or even in using them together, he did add something of value to the mix: marketing. Staying on top of web technologies is a full-time job, and the term Ajax made it easy to classify and communicate a more advanced breed of rich-client development methodologies. The cornerstone of Ajax,
Since then, Ajax has become synonymous with
XMLHttpRequest, which is what allows you to contact the server on demand ...