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Double-click any .md file and Hashpane renders it instantly into clean, GitHub-accurate text, right on your Mac. No accounts, no setup, no clutter. Just your document.

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weekly-notes.md

Weekly notes

A quick tour of GitHub Flavored Markdown, rendered exactly the way GitHub shows it. No surprises, no broken tables.

This week

  • Tables with alignment
  • Task lists and footnotes1
  • Ship the release
FeatureStatusEngine
Rendering✅instant
Highlighting✅Shiki
Math✅KaTeX
export function render(doc: string): Rendered {
  return pipeline.process(doc); // real syntax highlighting
}

Front matter is kept out of the rendered text, never dumped into the document body.

Footnotes

  1. Footnotes render with backlinks, just like GitHub. ↩

Real output: tables, task lists, footnotes, and syntax-highlighted code, exactly as GitHub shows them.

Powered by KaTeX

Math, beautifully typeset.

Inline and display equations render with KaTeX: integrals, matrices, Greek letters, and the full LaTeX vocabulary, crisp at any size. Ideal for papers, lecture notes, and READMEs that do real math.

  • ✓ Inline like $E = mc^2$ and standalone display blocks
  • ✓ Matrices, sums, integrals, and operators
  • ✓ Rendered instantly the moment a document opens
paper.md

Mathematical typesetting

Inline math like E=mc2E = mc^2 flows right inside a sentence, and display equations stand on their own, beautifully typeset with KaTeX.

Maxwell’s law, with the displacement current:

∇×B=μ0J+μ0ε0∂E∂t\nabla \times \mathbf{B} = \mu_0 \mathbf{J} + \mu_0 \varepsilon_0 \frac{\partial \mathbf{E}}{\partial t}

The Gaussian integral and the Basel sum:

∫−∞∞e−x2 dx=π∑n=1∞1n2=π26\int_{-\infty}^{\infty} e^{-x^2}\, dx = \sqrt{\pi} \qquad \sum_{n=1}^{\infty} \frac{1}{n^2} = \frac{\pi^2}{6}

A rotation matrix, and the most elegant equation in mathematics:

R(θ)=(cos⁡θ−sin⁡θsin⁡θcos⁡θ)eiπ+1=0R(\theta) = \begin{pmatrix} \cos\theta & -\sin\theta \\ \sin\theta & \cos\theta \end{pmatrix} \qquad e^{i\pi} + 1 = 0

One job, done precisely.

  • Open and read

    Double-click a Markdown file and it opens instantly, beautifully rendered. No setup, nothing to save, no clutter.

  • GitHub-accurate

    What you see is what GitHub shows. Tables, task lists, fenced code, footnotes, and math, all faithful.

  • Copy precisely

    Select any part of a document and copy it as formatted rich text, or as the exact Markdown source.

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There are no accounts and no sign-in, and no telemetry or analytics of any kind. Hashpane runs in the macOS App Sandbox and only ever reads the files you open, never modifying them or writing anything back. Your documents are plain text on your disk, and they stay yours.

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