YAMLIT (Yet Another Meta-Language Indentation Tool) was intended to provide a general purpose meta-language (HTML, XML, etc.) indentation (and un-indentation) tool.
The parser was written in such a way that it did not validate the DTD/XSD and therefore any additional processing tags (e.g. Freemarker) could be present in the file.

At this moment this project is not actively developed.
I suggest you install Eclipse and add the relevant language plugins and formatters.