A.E.P. is an Ajax framework that is very easy to use with an interface of six functions and these functions allow to build Web pages that are extended at user request from data hidden into the page or taken from external files. Text is extended at a word or as a whole.
Once you have experienced the library you feel obliged to build all your web page in this way, as I do. The web page of the library on the xul.fr site is extensible and almost all future pages on the site will be also. A modern web page now typically will include expand, collapse and print buttons (or links) for the convenience of visitors.
A short tutorial is provided in HTML and PDF forms.
The archive includes some small demos you can use to start with the tool.