The Open Markup project defines an open API called Open Markup
Interface for object realizers and XML object realization.

Object realization is a process by which software objects are created,
configured, and processed according to machine-readable descriptions of
those objects. It includes post-instantiation tasks, such as
configuring objects with additional attributes or properties,
connecting them with other objects to create complex object
compositions, or otherwise manipulating them according to control
information embedded in the object descriptions.