A tool surfaced this week on Hacker News called Pele (pele.run) that takes Mermaid diagram markup — the plain-text syntax widely used to describe flowcharts, sequence diagrams, and network maps — and renders the output as Scalable Vector Graphics (SVG) files that can be styled with custom themes. Unlike standard Mermaid rendering, which typically outputs fixed-style images or requires a live JavaScript environment to display, Pele produces SVG that accepts CSS-level theming, meaning the visual presentation can be adjusted without re-running the underlying diagram logic.
The project was shared on Hacker News in October 2026 and drew attention in the open-source diagramming community. Mermaid itself has become a broadly adopted standard, with native support baked into platforms including GitHub, GitLab, Notion, and Obsidian, making its plain-text syntax a kind of lingua franca for technical documentation. Pele's specific contribution is the SVG portability layer: an SVG file is self-contained, resolution-independent, and renderable in any modern browser or vector graphics application without a network connection or runtime dependency.
The theming capability means organizations or individuals can apply consistent visual branding — color schemes, fonts, line weights — across a library of diagrams without editing each one individually. The SVG output also means diagrams can be printed at any scale without quality loss, embedded directly into PDF documents, or archived in a format that does not depend on any particular software remaining available.
What makes this worth noting beyond the usual developer-tooling beat: Preppers and resilience-minded households increasingly maintain offline documentation — wiring diagrams, water system maps, communication trees, generator load charts — and the choice of file format for that documentation matters more than most people consider. SVG files are plain XML text under the hood, meaning they remain readable and editable even with nothing more than a text editor if dedicated software is unavailable. A Mermaid-to-SVG pipeline like Pele allows someone to maintain those diagrams in a human-readable plain-text source format (.mmd files), then export archival-quality vector images that will render correctly decades from now on essentially any display technology. That combination of plaintext source and self-contained vector output is a meaningful resilience property that PNG screenshots or cloud-hosted diagram tools do not share. For those already building out offline documentation kits, our offline documentation guide covers file format considerations in more depth.
