This library provides a foundation for building XHTML hypermedia API
clients. The major notion of a hypermedia API is that clients start from
a known entry-point URL and proceed to use the API by following links and
submitting forms--exactly the way humans do when they use the web. This
style of API provides a lot of server-side flexibility in terms of
controlling its own URL space, since clients never construct URLs
themselves. Instead, clients construct their HTTP requests by following the
existing, standardized semantics for HTTP <a> and <form> elements, which
means the mechanisms for those requests are under the server's control.

See also the "Hypermedia APIs" talk given by Jon Moore at Øredev 2010:
http://oredev.org/2010/sessions/hypermedia-apis