CXF uses JAXB 2.x as its default databinding.
CXF also includes other data bindings. XMLBeans is available, and there is the Aegis data binding which will turn nearly any Java object into something that can be represented using schema, including Maps, Lists, and unannotated java types. Also, there is the SourceDataBinding for Source objects. CXF 2.3.0 adds an SDO data binding.