Originally, browsers could not easily fetch more data without
triggering a full page refresh. Perhaps the most important early approach
for solving the I/O problem came from Internet Explorer 5, which introduced a scriptable ActiveX
control for performing asynchronous HTTP requests. This feature evolved into
a common cross-browser object called
Fetching and Displaying XHR Data introduces
Y.io(), YUI’s wrapper for the classic XHR
Handling Errors During Data Transport runs through the various ...