New name, old game: ajax!

Ajax applications look almost as if they reside on the user's machine, rather than across the Internet on a server. The reason: pages get updated, not entirely refreshed.

“Every user action that normally would generate an HTTP request takes the form of a JavaScript call to the Ajax engine instead”, wrote Jesse James Garrett, in the essay that first defined the term. “Any response to a user action that doesn’t require a trip back to the server — such as simple data validation, editing data in memory, and even some navigation — the engine handles on its own. If the engine needs something from the server in order to respond — if it’s submitting data for processing, loading additional interface code, or retrieving new data — the engine makes those requests asynchronously, usually using XML, without stalling a user’s interaction with the application.”

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