The Betwixt library provides an XML introspection mechanism for mapping beans to XML in a flexible way. It is implemented using an XMLIntrospector and XMLBeanInfo classes which are similar to the standard Introspector and BeanInfo from the Java Beans specification.

Betwixt provides a way of turning beans into XML as well as automatically generating digester rules in a way that can be customized on a per type manner in the same way that the BeanInfo mechanism can be used to customize the default introspection on a java object.