Ask HN: General Purpose Templating Engine

The title attempts to distill the essence of the question, however, I suspect my lack of terminology in this area may make things more difficult.

What I'm looking for is a standalone general purpose templating engine. I envision this to meet the following criteria

- Available as a single binary with a CLI interface

- Ingests common data formats (i.e. JSON, etc.)

- Exports textual data of any format

The primary use-case is not generating HTML, but rather various textual data with differing structural requirements. It's very hard to search in this space because you're inevitably met with Javascript solutions aiming to template HTML. I'd prefer not to be tied to a JS runtime and the idiosyncrasies of trying to template HTML.