📜 carta

A universal document converter written in Rust that reads a markup format and renders it back out in another. A performant and lightweight reimplementation of pandoc.

[!WARNING] carta is a prototype under active development. Only a small slice of pandoc's formats is implemented today, the API is unstable, and it is not yet ready for production use.

Goals

Performance and a smaller binary than pandoc.
Feature parity with pandoc across all formats and extensions.
A developer-friendly library, with the CLI as a thin shell over it.

Status

This tracks carta's status of all formats pandoc supports. See STATUS.md for a detailed per-format breakdown including extension coverage, and the full feature backlog.

✅ usable — basically done; any remaining parity gaps are minor and unlikely to affect regular use · 🚧 in development — large parity gaps or breaking issues (e.g. panics), not recommended for use yet · ❌ not started · ➖ not applicable (pandoc has no such direction)

Markdown family

Format	Reader	Writer
CommonMark (`commonmark`)	✅	✅
CommonMark-X (`commonmark_x`)	✅	✅
GitHub-Flavored Markdown (`gfm`)	✅	✅
Pandoc Markdown (`markdown`)	✅	✅
Markdown strict (`markdown_strict`)	✅	✅
MultiMarkdown (`markdown_mmd`)	✅	✅
PHP Markdown Extra (`markdown_phpextra`)	✅	✅
GitHub Markdown, legacy (`markdown_github`)	✅	✅
Djot (`djot`)	❌	❌
Markua (`markua`)	➖	❌

HTML & slides

Format	Reader	Writer
HTML (`html`, `html5`, `html4`)	✅	✅
Chunked HTML (`chunkedhtml`)	➖	❌
reveal.js (`revealjs`)	➖	✅
Beamer (`beamer`)	➖	✅
Slidy (`slidy`)	➖	❌
S5 (`s5`)	➖	❌
Slideous (`slideous`)	➖	❌
DZSlides (`dzslides`)	➖	❌
PowerPoint (`pptx`)	❌	❌

TeX & typesetting

Format	Reader	Writer
LaTeX (`latex`)	✅	✅
Typst (`typst`)	❌	✅
ConTeXt (`context`)	➖	❌
Texinfo (`texinfo`)	➖	❌
PDF (`pdf`)	➖	❌

Lightweight markup

Format	Reader	Writer
reStructuredText (`rst`)	✅	✅
AsciiDoc (`asciidoc`)	❌	✅
AsciiDoc legacy (`asciidoc_legacy`)	➖	❌
Asciidoctor (`asciidoctor`)	➖	❌
Org mode (`org`)	✅	✅
Textile (`textile`)	❌	❌
Muse (`muse`)	❌	❌
Haddock (`haddock`)	❌	❌
txt2tags (`t2t`)	❌	➖
Perl POD (`pod`)	❌	➖

Wikis

Format	Reader	Writer
MediaWiki (`mediawiki`)	✅	✅
DokuWiki (`dokuwiki`)	✅	✅
Jira (`jira`)	✅	✅
Creole (`creole`)	❌	➖
TikiWiki (`tikiwiki`)	❌	➖
TWiki (`twiki`)	❌	➖
Vimwiki (`vimwiki`)	❌	➖
XWiki (`xwiki`)	➖	❌
ZimWiki (`zimwiki`)	➖	❌

roff

Format	Reader	Writer
man (`man`)	✅	✅
mdoc (`mdoc`)	❌	➖
ms (`ms`)	➖	❌
vimdoc (`vimdoc`)	➖	❌

Word processor, ebook & notebook

Format	Reader	Writer
Word (`docx`)	❌	❌
OpenDocument Text (`odt`)	❌	❌
OpenDocument (`opendocument`)	➖	❌
EPUB (`epub`, `epub2`, `epub3`)	❌	❌
Jupyter Notebook (`ipynb`)	✅	🚧
FictionBook2 (`fb2`)	❌	❌
InDesign ICML (`icml`)	➖	❌
Rich Text Format (`rtf`)	❌	❌
Spreadsheet (`xlsx`)	❌	➖

XML & publishing

Format	Reader	Writer
DocBook (`docbook`, `docbook4`, `docbook5`)	❌	❌
JATS (`jats`, `jats_archiving`, `jats_articleauthoring`, `jats_publishing`)	❌	❌
BITS (`bits`)	❌	➖
TEI (`tei`)	➖	❌
Generic XML (`xml`)	❌	❌

Bibliography

Format	Reader	Writer
BibTeX (`bibtex`)	❌	❌
BibLaTeX (`biblatex`)	❌	❌
CSL JSON (`csljson`)	❌	❌
RIS (`ris`)	❌	➖
EndNote XML (`endnotexml`)	❌	➖

Data, interchange & terminal

Format	Reader	Writer
Pandoc JSON (`json`)	✅	✅
Native Pandoc AST (`native`)	✅	✅
OPML (`opml`)	✅	✅
CSV (`csv`)	✅	➖
TSV (`tsv`)	✅	➖
Plain text (`plain`)	➖	✅
BBCode (`bbcode`, `bbcode_phpbb`, `bbcode_steam`, …)	➖	❌
ANSI terminal (`ansi`)	➖	❌

Installation

Prebuilt binaries

Download the archive for your platform from the latest release. Builds are provided for Linux (x86-64 gnu and static musl, arm64), macOS (Intel and Apple Silicon), and Windows (x86-64).

From crates.io

cargo install carta

This installs the carta binary. For a smaller build, pass --no-default-features with only the formats you need, e.g. --features cli,read-commonmark,write-html.

From source

git clone https://github.com/mfkrause/carta
cd carta
cargo build --release
# binary at target/release/carta

Usage

Command line

# CommonMark to HTML
carta -f commonmark -t html input.md -o output.html

# read from stdin, write to stdout
echo '# Hello' | carta -f commonmark -t html

# inspect the document model
carta -f commonmark -t json input.md

# standalone document with a table of contents and numbered sections
carta -f commonmark -t html -s --toc --number-sections input.md -o output.html

# render HTML math with MathJax (or --katex)
carta -f commonmark -t html -s --mathjax input.md -o output.html

# discover what this build supports
carta --list-input-formats
carta --list-output-formats
carta --list-extensions          # extensions for the Markdown dialect
carta --list-extensions=gfm      # extensions and defaults for a given format

Library

use carta::{convert, ReaderOptions, WriterOptions};

let html = convert(
    "commonmark",
    "html",
    "# Hello, *world*",
    &ReaderOptions::default(),
    &WriterOptions::default(),
)?;

You can select formats at compile time via per-direction features to make binaries even more lightweight for your individual needs.

cargo build -p carta --no-default-features --features read-commonmark,write-html

Development

cargo build                         # build the workspace
cargo nextest run --workspace       # run tests
cargo clippy --all-targets          # lint
cargo +nightly fuzz run commonmark  # fuzz a reader (see fuzz/README.md)

The workspace splits into carta-ast (the document model), carta-core (shared traits and options), carta-readers, carta-writers, and carta (the library facade, which also ships the command-line binary behind its cli feature).

License

carta is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License, version 3, as published by the Free Software Foundation. See LICENSE for the full text.

carta-readers 0.0.1