HV WDDX Metadata is a class using the WDDX format
to describe data for generating user interfaces.
From the WDDX data, any type of markup (including
XUL) can be generated using XSLT. The generated
markup can describe an entry form, for example.
The data entered by the users in the generated
forms can be validated on the client side using
Javascript, or on the server side by PHP using
regular expressions defined in the WDDX
configuration file. It requires the XSLT module
and the PEAR.php base class.