Xtempore is a lightweight, modular, and powerful XML-based domain independent templating language. It's essentially a programming library which provides flexible tools for transforming an object (model) and an XML document (template) into another XML document. Xtempore is implemented in Java and requires JRE 1.5 or later and slf4j for logging.
gedcom4j is a Java library for loading (parsing) and saving GEDCOM 5.5 or 5.5.1 files to/from a Java object hierarchy, which can be manipulated by your code as you see fit. Please note that gedcom4j is not an application. It is a library for parsing, manipulating, and writing GEDCOM data in your own programs.