AI writes it.
You're the one reading it.

Opening	Instant. There's no loading screen, because there's nothing to load.
While you read	Uses no processor time at all. The fan stays off; your battery doesn't notice it's open.
Memory	~127 MB with nine large documents open at once — and ~52 MB handed back the moment you close them. It doesn't creep up over the day.
Big files	A 4,000-paragraph document opens right away, and the scrollbar tells the truth about its length from the first frame.
Diagrams	Flowcharts and sequence diagrams appear right in the page, even with no internet. Drawn once, instant every time after.
Images	Scroll past a picture and it quietly gives its memory back; scroll up and it's there. The page never jumps while you read.
Code	Colored the way your editor colors it, with a Copy button on every block.
Reading	Tabs, find (⌘F), bigger or smaller text (⌘+/⌘−), automatic dark mode.
Editing	Right-click a block, or press E to edit · I to add below · U/J to move · D to delete. Your changes are yours until ⌘S.
Finding your place	T opens a list of every heading. Click one and the cursor goes there, ready to edit that section.
Editing big files	Only the block you changed is redrawn — 9 ms on a 64,000-character file, 29 ms on 1.2 MB. Undo stays instant.
Word & OpenDocument	Opens .docx · .docm · .dotx · .dotm · .odt read-only, shown as the author formatted it — headings, tables whose columns line up, images and equations even inside a cell, footnotes, comments, tracked changes and right-to-left text. Want to change one? One click hands it to your editor of choice.
Extract for an AI	--extract turns a .docx or .odt into clean Markdown from the command line — headless, so an AI reads it without spending its budget parsing the file.
Plain text	Opens .txt · .csv · .log too, shown exactly as written. Files from Windows or Linux arrive readable — saved back in the encoding they came in.
Works on	Macs with Apple silicon (M1 and later), macOS 13 or later.
Price	Free — and the source is public, so every number here is something you can check yourself.

Jump by the document's own units

The arrow keys move you by the units a document is actually made of, and the modifier decides how far you go. A soft band follows the line you're on, so a glance finds your place after a scroll — and the page holds still while the cursor moves inside it, following only when the cursor would leave the screen.

⌘↑ ⌘↓	Previous / next heading — step through the document's own outline.
⌥↑ ⌥↓	Page up / down, with a few lines of overlap so you keep your place.
fn↑ fn↓	Straight to the start or end of the document.
⌘← ⌘→	Start / end of the line.
⌥← ⌥→	Previous / next sentence.
fn← fn→	Previous / next paragraph.A whole table or code block counts as a single stop, so you step over it instead of through it.
↑ ↓ ← →	Move the reading cursor one line or one character.
⇧ + any of these	The same move, selecting as it goes.Jump three paragraphs with ⇧fn→ and you have those three paragraphs selected, ready to copy.
?	The full list, inside the app.Every shortcut here — plus find, zoom, tabs and the mouse ones — without leaving the document.

Take a section without selecting it

Dragging a cursor across three screens to copy one section is the other half of the job. So the left margin does it for you — click it, and the block beside it is on your clipboard, highlighted so you can see exactly what you got.

Beside a heading	The whole section — down to the next heading of the same rank or higher.Sub-headings underneath come along; the next sibling section never does.
Beside a code block	The raw code — what you'd paste into a terminal, not the rendered card.
Beside anything else	That paragraph, list or table, on its own.
Right-click a block	Copy · Open · Edit · Add Below · Move · DeleteEditing opens that block's Markdown source. Nothing reaches the file until ⌘S.

Change a block without leaving the page

The same five keys work wherever the reading cursor is, so fixing a line or moving a section never means picking up the mouse. Every step is one undo, and the page keeps your place — only the block you touched is redrawn, which is why it stays instant in a file where other apps stall.

E	Edit this block's Markdown source.
I	Insert a new block below it.
U · J	Move it up · down, a step per press.
D	Delete it — asked first, and undoable after.With a selection, everything it touches goes at once.
T	A sidebar of every heading. Click one and the cursor lands there, ready to edit that section.
⌘S · ⌘N	Save · new file.A new Markdown file starts with a small outline, so there is something to edit from the first keystroke.