Latex Document Portability: Creating Future-Proof Documents

Portability refers to the ability of a LaTeX document to be compiled and rendered correctly across different LaTeX distributions, operating systems, and devices. A portable document avoids reliance on specific TeX implementations, local file paths, or niche packages. Instead, it focuses on widely-adopted packages, standard document classes, and separation of content from presentation formatting.

Defining Portability in LaTeX

A portable LaTeX document is one that can be shared across collaborators, devices, and time while maintaining rendering fidelity. The goal of portability is to future-proof documents against changes in LaTeX distributions and component versions. Two key enablers of portability are standardization and parameterization.

What does “portability” mean for LaTeX documents?

For a LaTeX document, portability refers to:

Table of Contents

Correctly compiling to PDF or other output formats across different LaTeX installations
Rendering visual formatting consistently on different viewers and devices
Gracefully handling co-authorship across different affiliations
Accommodating updates over long publication lifecycles
Conforming with accessibility guidelines to reach wide audiences

The role of standard packages and document classes

To maximize portability, LaTeX documents should leverage standard components like the article or book document classes. Reliance on niche packages from specific installations or local paths leads to fragility. Instead, widely-adopted packages from the Comprehensive TeX Archive Network (CTAN) ensure consistency.

Common Causes of Poor Portability

Certain LaTeX practices inhibit document portability across collaborators, systems, and time. The three most frequent culprits are outdated packages, hardcoded formatting, and local file path dependencies.

Using outdated or niche packages

Packages directly introduce dependencies into a LaTeX document. Unfortunately, maintaining long-term access to niche or unmaintained packages is difficult. Relying on anything besides widely-used packages from CTAN risks future compatibility issues.

Hardcoding text formatting

Hardcoded formatting elements like font families, text sizes, line spacing, etc. often reflect local style preferences. These decrease portability by amplifying subtle differences in renderer implementations across systems. Furthermore, changes require manually identifying and changing all occurrences.

Embedding local file paths

Referencing files via absolute file paths creates a dependency on folder structures remaining unchanged. Portable LaTeX relies on relative paths between component files that move together. Avoid \includegraphics with absolute paths to local systems.

Best Practices for Portable Documents

Creating durable and portable LaTeX documents requires upfront planning and an emphasis on flexibility. Some key best practices include leveraging standard classes, sticking to common packages, and parameterization.

Leverage standard document classes like article, book, etc.

The article, book, and report document classes offer maximum portability with simple, consistent interfaces for controlling structure and formatting. Custom document classes risk compatibility issues down the line unless carefully designed for reuse.

Favor widely-used packages from CTAN

Relying on well-established, maintained LaTeX packages from CTAN improves the changes of long-term compatibility. Packages like graphics, geometry, hyperref, and others have proven reliable across major TeX distributions.

Parameterize formatting choices

Make use of LaTeX macros and custom commands to encapsulate and parameterize styling decisions for text elements. For example, define \sectionTitleFormatting and \bodyTextFormatting commands instead of hardcoding choices.

Separating Content and Presentation

To improve maintainability and portability, LaTeX best practices dictate separating document content and presentation/formatting concerns. Treat LaTeX as a semantic markup language rather than just a processor for outputting beautifully typeset PDFs.

Use LaTeX semantics for structure

Leverage built-in LaTeX document semantics like \section, \subsection to mark up structure instead of manually formatting content to simulate visual hierarchy. Rely on LaTeX's renderer to transform structural semantics into actual visual presentation.

Store style choices in preamble

Keep all style decisions regarding fonts, spacing, sizing, colors, etc. abstracted out into the preamble. The document body should focus exclusively on structure and content semantics without any hardcoded formatting.

Example document structure

A properly structured LaTeX document uses consistent semantics in the body while consolidating all styling customization into preambles and imported style packages:

\begin{verbatim}
\documentclass{article}

% Preamble with package imports, macros, etc.
\usepackage[T1]{fontenc}

\newcommand{\sectionHeaderFormat}{\large\bfseries}

\begin{document}

% Structural body content only
\sectionHeaderFormat{Introduction}

Leverage \LaTeX's structural elements without any hardcoded styling. Keep things portable!
\end{verbatim}

Testing Portability with Continuous Integration

Continuous integration (CI) refers to automatically compiling, building, and verifying documents after changes. CI quickly surfaces portability issues before collaborators get out of sync.

Configuring CI for \LaTeX

Tools like Travis CI and GitHub Actions can compile \LaTeX on commit or merge. The CI checks for compiler warnings and errors using headless engines like pdfLaTeX.

Catching portability issues early

Even tiny pull requests can introduce portability regressions through new packages or incompatible code. CI gives quick feedback to authors, maintaining document health.

Example Travis CI config file

This .travis.yml file configures Travis CI to build the LaTeX document on every push to GitHub:

language: python 

install:
  - pip install latexmk

script:
  - latexmk -pdf example_doc.tex

Troubleshooting Portability Issues

When a LaTeX document compiles locally but fails on CI or another system, the culprit is often portability. Strategic debugging helps identify problematic packages or code.

Debugging failing LaTeX builds

Failed CI builds display compiler output detailing errors like undefined commands, missing packages, or file access issues. Compare this against the local build log.

Identifying outdated or incompatible packages

If a document references deprecated commands, suspect outdated imported packages. Check CTAN for package revisions or updates. Inspect version drift across collaborating authors' systems.

Strategies for package version management

Consider explicitly tracking package versions used or even vendoring packages into the document repository itself to strictly manage changes.

Creating LaTeX Documents for the Future

LaTeX's durability owes greatly to portability best practices that stand the test of time across authors, affiliations, systems, and distribution versions. Plan documents intentionally for multi-decade usefulness.

Planning for long-term maintenance

Treat LaTeX documents as software projects that evolve over years rather than static, bounded works. Design with flexibility for future authors to update content, style, build processes, etc.

Accommodating co-authors across institutions

Collaborating authors may work across operating systems, TeX distributions, and repository infrastructures. Emphasize standard LaTeX build tooling to minimize friction integrating contributions.

Ensuring accessibility of documents

Well-structured documents with proper alt-text, tags, logical reading order, color contrast, etc. guarantee access for readers relying on assistive devices - now and decades from now.