XML Binding Language (XBL) 2.0
The XML Binding Language (XBL) describes the ability to associate elements in a document with script, event handlers, CSS, and more complex content models, which can be stored in another document. This can be used to re-order and wrap content so that, for instance, simple HTML or XHTML markup can have complex CSS styles applied without requiring that the markup be polluted with multiple semantically neutral div elements.
XBL 2.0 defines a namespace associated with the URI http://www.w3.org/ns/xbl
Ample SDK implementation details
At the present moment XBL 2.0 in Ample SDK is in the development.