This repository is not a conventional software application; it is the LaTeX source for “An Infinitely Large Napkin,” an open-access advanced mathematics textbook by Evan Chen. The codebase contains 100+ chapter files spanning group theory, topology, algebraic geometry, number theory, set theory, measure theory, representation theory, and quantum algorithms, all written in a consistent pedagogical style with custom macros (\vocab, \prototype, \moral, difficulty markers). The primary deliverable is a compiled PDF (Napkin.pdf), produced through a documented build pipeline involving latexmk, Asymptote graphics, and vendored LaTeX packages. Because the repository also includes CLI scripts, a Nix build definition, and GitHub Actions workflows for automated compilation and deployment, it is best categorized as an application-style document-publishing project rather than a data/research repository. The build system is the most software-like part: `.latexmkrc` configures latexmk with Asymptote support, `flake.nix` provides a reproducible Nix derivation, and `.github/workflows/napkin.yml` compiles the book, extracts a TOC, splits the PDF into per-part files with qpdf, and deploys to GitHub Pages. `print-toc.py` is a self-contained Python utility that parses LaTeX `.toc` files and generates splitting commands, useful beyond this specific project. The mathematical content itself is substantial and well-organized, but it is explicitly an “incomplete draft”: multiple chapters contain TODO markers, missing proofs, and planned-but-unwritten sections. The repository is actively maintained (recent commits and CI runs), though the large number of cross-references and custom packages creates some fragility in the build. No data pipelines or empirical datasets exist here; the research-like aspect is purely mathematical exposition and citation of external textbooks. For an AI agent or engineer, the reusable value lies in the LaTeX book publishing infrastructure (Nix, CI, PDF-splitting scripts) and potentially in the well-tested pattern of macros and theorem environments for typesetting mathematics.
This is the web application powering the Journal of Open Source Software (JOSS), a diamond open-access journal that publishes peer-reviewed papers about research software. It is a monolithic Ruby on Rails application (Rails 7.2 / Ruby 3.3) that manages the complete lifecycle of academic submissions, from author submission through editorial review, publication, and DOI minting. The system is deeply integrated with the GitHub API (via Octokit) to manage review issues, labels, and comments, effectively using GitHub as a collaboration platform for the peer review process. It features a sophisticated state machine for paper workflows (submitted, under review, accepted, rejected, retracted), ORCID-based authentication, Elasticsearch-powered search, and automated notification emails. Key architectural components include a webhook dispatch controller for processing GitHub events, a feature flag system (JournalFeatures), a blocklist for preventing spam submissions, and a structured editorial board management system with tracks and subjects. The frontend uses Bootstrap 4.3.1 with Hotwired Turbo and custom JavaScript. Background tasks are handled by Rake tasks (cron jobs via Heroku Scheduler). While the core application is well-maintained and actively developed, it shows signs of technical drift in its frontend dependencies (Bootstrap 4, jQuery) and relies on a custom Rails configuration DSL. The codebase is well-tested with RSpec and system specs, making it a robust platform for its specific domain.