I answered an FAQ question tonight on the HTML_AJAX wiki, im posting the answer here as well since I know most people don’t check the wiki for changes every day.
Outside of this answer I’d like to hear from what other libraries people would like too see integrated with HTML_AJAX and the reasons for this.
Most integration would take place in higher level components. Its unclear weather higher level components like that should be part of HTML_AJAX delivered through PEAR or if they should just be supported by HTML_AJAX and made available from http://htmlajax.org or some other site. If your interested in building widgets or components based on HTML_AJAX please let me know.
To do this you just need to register the library with your server and load add its flag to your include line.