[flomo]

And XMLHttpRequest was the replacement for an earlier applet-based method called 'Remote Scripting', which was pulled when MS lost the Java lawsuit. (And contrary to what DougWebb said, it worked pretty well.)

Remote Scripting itself was a copy of an IBM applet which Netscape pushed in the v4 timeframe (although practically, NS4 was too unstable to do any real dynamic html.)

So it really was the "AJAX" branding effort that got devs to notice what had been under their noses for some time.

("MSRS" now stands for something else entirely, but here's an old article discussing pre-historic AJAX techniques: http://www.ibm.com/developerworks/web/library/wa-resc/ )