Typed XML over HTTP has many benefits:
it combines the properties of HTTP with the simplicity,
flexibility and reusability
of XML, and the type information (be it
the older DTD or just informal),
provides isolation across customers and producers.
Simplicity is key:
it is possible to quickly write a consumer or producer for this class of services
in almost any language,
including AJAX clients.
And what has been missing is a simple, standard way to describe
(WSDL is too complex)
the services that can be used to advertise them and that can be used by different tools.
fills in this gap, and Marc just
an Open Source project around this effort.
There are many opportunities for contributions;
I personally would like to see tools for languages different than Java,
and using annotations to further simplify the
Map to Java.
You could also help start cataloging more servicers available in the web;
you do not even need to use XSD, WADL supports also Relax NG.
And, if your site is a Web Services producer, I would encourage you to include a WADL
description of your service.
Some people use the term
to mean any typed XML over HTTP;
the two are related but REST also implies some other architectural contraints,
although WADL be very useful in implementing RESTful services.
For more info, check older
as well as