The ULM.gen (Ultra-Lite Modeling generator) project is a simple framework intended to help building and customizing source-code generators from a UML model expressed as XML documents, using generation templates. Because it makes use of generation templates, it can also easily be used to generate documentation in HTML, DocBook or other standard-based document formats.

It is also expected that feed-back information can be produced in return: for instance, a generation template can produce a UML interchange document intended to update the model, this feature can be used to automatically apply design patterns to an existing model. Source code generation can also analyze the previous generation result in order to preserve code regions that are intended to be implemented by developers.