The beginnings of Ajax as used today started with the release of
Internet Explorer 5 in 1999, which introduced a new ActiveX object,
XMLHttpRequest. ActiveX is Microsoft’s
technology for signing plug-ins that add additional software to the user’s
computer. Other browser developers later followed suit, but rather than
using ActiveX, they all implemented the feature as a native part of the
However, even before then, an early form of Ajax had already surfaced that used hidden frames on a page that interacted with the server in the background. Chat rooms were early adopters of this technology, using it to poll for and display new message posts without requiring page reloads.