The Mardo blog
Engineering stories from Floof Logic about Mardo, the native Markdown viewer and editor for the Mac: what it does, how it got fast, and why.
- Mardo 1.0: a Mac Markdown app that launches faster than Apple's own text view. Mardo 1.0 is a native Mac Markdown app that launches faster than Apple's own text view, opens 50 GB files, and makes room for the AI agents editing your files.
- Why bullets vanish when you paste Markdown into LinkedIn. Bullets vanish in LinkedIn because it flattens the pasted HTML list, which never held a bullet character, so Mardo 0.9.26 copies lists with the bullets written in.
- Mardo launches in 108 ms, faster than a matched NSTextView. Mardo's Mac app launch time fell to a median 108 ms, faster than a matched NSTextView, once we saw that whoever touches AppKit first pays for AppKit.
- Any jump into a 50 GiB Markdown file reads at most 88 KB before you see it. Mardo, a native Markdown app, opens a 50 GiB file on a Mac without freezing; any jump puts its text on screen in under 13 ms, reading at most 88 KB to get there.
- How to preview Markdown files in Finder with Quick Look, for free. Finder shows Markdown as plain text; Mardo's free Quick Look extension renders it natively when you press Space, and here's how to turn it on if it doesn't.
- Mardo opens MDX, Quarto and R Markdown files on a Mac. Mardo 0.9.21 opens MDX, Quarto and R Markdown files on a Mac through the same reader as .md, in the app, Quick Look, Terminal and MCP, and never runs their code.
- What did the AI agent just change in my file?. Mardo's Timewarp lets you see what an AI agent changed in a file you have open, save by save, without copying the file once, using clones it used to throw away.
- An MCP Markdown viewer that Claude Code and Codex can drive directly. Mardo is a Mac Markdown viewer that Claude Code and Codex drive over local MCP with no network port, showing exact lines on screen and returning only a receipt.
- AppKit quietly shrinks views taller than 10 billion points. AppKit stops a constraint-sized view at ten billion points. Past that limit, Mardo 0.9.12 opens a 50 GB Markdown file, reaches its last byte and searches it in 37 s.
- Syntax color and custom Markdown themes on the Mac that never move your caret. Mardo 0.9.10 adds syntax color to Source Code and custom Markdown themes you can make and share, and both change only the ink, never a caret, a click or a byte.
- Mardo, a native Mac Markdown editor, met all 27 speed budgets at its slowest. Mardo 0.9.0, a fast native Markdown editor for the Mac, met all 27 of its speed budgets on the slowest sample, and its worst of 10,000 keystrokes took 8.53 ms.
- 800 MB to show an 8 MB file. Why our Mac Markdown reader needed 800 MB to show an 8 MB file, and how a bounded viewport brought it down to 27.