Mac App Store · Coming Soon

Think in plain text. Ship in print.

DownSide is a native macOS markdown workspace built for people who live in .md files — instant preview, folder-native organization, and export that actually looks like a finished document. No accounts. No sync drama. Just your words on disk.

Download on the Mac App Store Coming Soon Why plain text wins →

Platform: macOS 15+
Storage: Your files, your folders
Export: HTML · Print · PDF
By: AltaForma

Why DownSide

Built for writers who never stopped trusting plain text.

You don't need another database pretending to be a notebook. You need a Mac app that opens instantly, respects your folder structure, and makes markdown feel inevitable — from the first keystroke to the printed page.

⌁

Opens instantly

Open a folder, start typing. Live search across your vault. Autosave keeps up with your thinking. The UI stays out of the way until you need it.

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Live preview, real typography

Swiss Strict styling baked in — crisp headings, deliberate hierarchy, light and dark preview. Bring your own CSS when you want to go further.

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Folder-native workflow

Your notes live where you put them — iCloud, Dropbox, a USB stick. DownSide doesn't lock you into a proprietary format or a hosted silo.

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Wiki links that work

Connect ideas with [[double-bracket links]] between files in the same workspace. Build a personal knowledge graph without leaving the editor.

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Math, diagrams, code

KaTeX for equations, Mermaid for diagrams, Prism for syntax highlighting. Technical writing stays first-class, not bolted on.

↗

Export without ceremony

Standalone HTML, print preview with real page setup, multi-page PDF from your preview styles. What you see is what leaves your machine.

Keyboard-first Plain-text forever Research notes Technical docs Zettelkasten-curious Print-ready prose

The Philosophy

Files on disk beat databases in the cloud.

The best note systems feel invisible: a blinking cursor, a filename you chose, a preview that proves the words landed right. DownSide is Swift and SwiftUI on Apple silicon — WebKit for rendering, AppKit for the chrome that matters. No Electron. No subscription. No sync server to babysit.

Write in monospace. Preview in Swiss typography. Export when the document is ready to meet the world. That's the whole job.

0 Cloud accounts

100% Local files

∞ Your folders

# meeting-notes.md Quarterly planning Context 04 Three themes for Q3: focus, ship, polish. 05 Budget locked. Headcount flat. Decisions 07 - Launch DownSide beta in September 08 - Keep the editor native; no web client 09 - [[print-pipeline]] owns PDF quality bar Next 11 See [[roadmap]] for milestone dates.

The Interface

Editor on the left. Truth on the right.

A split workspace that feels like a proper Mac app — folder sidebar, monospace editor, live preview inspector, and a toolbar that respects your muscle memory.

Write & preview

Type markdown in a focused editor with syntax-aware highlighting. Preview updates as you write — scroll sync optional, distraction always off.

DownSide — notes.md

Editor

1 # Launch brief 2 3 Ship when the preview 4 matches the print output. 5 6 ## Timeline 7 - Beta: September

Preview

Screenshot · Editor + Preview

Folder workspace

Open any folder on your Mac. Browse, create, rename, and search files without leaving the window. Your vault structure stays yours.

DownSide — Research

Editor

1 # Literature review 2 Sources in [[bibliography]].

Screenshot · Folder Browser

Print & PDF

Real print preview with margins, page breaks, and Swiss typography tuned for paper. Export multi-page PDFs from the same render engine — no surprise layout shifts.

Print Preview

Margins

Screenshot · Print Preview

Your styles, your rules

Built-in Swiss Strict CSS for screen and print. Layer custom preview, syntax, and print stylesheets. Dark preview when you're burning the midnight oil.

Preferences — Preview

Preview CSS

:root { --font-sans: SF Pro; } h1 { border-bottom: 4px; }

Live preview

Screenshot · Style Preferences

How It Works

Three steps. Zero ceremony.

From blank file to printed document without changing apps.

Open your folder

Point DownSide at the directory where your markdown already lives. Pick up exactly where you left off — no import wizard, no migration dance.

Write with preview

Compose in the editor, watch the preview prove your formatting, link between notes, drop in diagrams and math. Autosave handles the rest.

Ship it

Export HTML for the web, print from preview, or save a PDF that matches what you approved on screen. Your stylesheet goes with it.

Coming soon to the Mac App Store.

DownSide is in final polish — a native markdown workspace for people who chose plain text on purpose. Built by AltaForma.

Download on the Mac App Store Coming Soon

Questions? hello@alta-forma.com