////
Processing your document
Selecting an Output Format

This document is included in convert-documents and the user-manual.
////

The Asciidoctor processor is typically used to parse an AsciiDoc document and convert it to a variety of formats, such as HTML, DocBook, or PDF.
This section describes how to specify the output format.

The processor generates the output format using a converter.
Each converter is mapped to the name of a backend.
You specify the backend--and, in turn, the converter--using the `-b` (`--backend`) command line option or `backend` API option.
If no backend is specified, the processor uses the converter for the default backend (`html5`).

Asciidoctor provides several built-in converters, which are mapped to the following backend names:

html (or html5):: HTML 5, styled with CSS3 (default).
xhtml (or xhtml5):: The XHTML variant of the output from `html5`.
docbook (or docbook5):: DocBook 5.0 XML.
manpage:: Manual pages for Unix and Unix-like operating systems.

Asciidoctor also has several add-on converters, which can be plugged in by adding the appropriate library to the runtime path (e.g., `-r asciidoctor-pdf`).
These converters are mapped to the following backend names:

pdf:: PDF, a portable document format.
Requires the https://rubygems.org/gems/asciidoctor-pdf[asciidoctor-pdf] gem.
epub3:: EPUB3, a distribution and interchange format standard for digital publications and documents.
Requires the https://rubygems.org/gems/asciidoctor-epub3[asciidoctor-epub3] gem.
latex:: LaTeX, a document preparation system for high-quality typesetting.
Requires the https://rubygems.org/gems/asciidoctor-latex[asciidoctor-latex] gem.
mallard:: Mallard 1.0 XML.
Requires the https://github.com/asciidoctor/asciidoctor-mallard[asciidoctor-mallard] gem (not yet released).

There are also converters available for HTML5 presentation systems such as reveal.js and Bespoke.js.
Those converters are still in development and will be documented once releases become available.

// TODO describe the role of template converters (e.g., asciidoctor-backends)