Pandoc is a great text converter. A common use case for me is to covnert Markdown to PDF or HTML. Org mode can use Pandoc to convert Org files to PDF via LaTeX.
- Customizing pandoc to generate beautiful pdfs from markdown (mostly LaTeX settings)
- A ready-to-edit LaTeX template for book-style compilations — amberj/latex-book-template
- Writing a Book with Pandoc, Make, and Vim — Vladimir Keleshev