your code editor is mostly decoration.
A 14MB macOS code editor built around running coding agents: a terminal that takes the whole width, projects as tabs, git worktrees down the side, and an editor for when you actually need to read one of your files. That’s it — on purpose. It opens in 0.38s and has never once asked about your onboarding journey.
brew install --cask zero-editor/tap/zero Open source, MIT — all 21,596 lines of it on GitHub.
Apple Silicon · macOS 26 · no network code in the app
The bright bar is zero; the long one is Cursor — method and scripts →
The whole interface: projects across the top, their files one row down, a tree at the side, and a terminal that takes the full width. The ring on a project is its session — sweeping while something’s working, a closed circle when it’s done and waiting on you. No chrome; the buttons only appear when your pointer goes looking for them.
you always know what’s running.
Every project is a tab, and the ring on it is that project’s pulse — sweeping while something is running, a closed circle once it’s waiting on you. One look across the top and you know where everything stands.
Read from each shell’s process tree and how long the pty has been silent, once a second. Nothing to configure.
press record, ramble, press stop.
Talk at your project instead of typing at it. Your Mac writes down what you said, claude tidies it into the note you meant, and recording again folds the new thoughts in. Four minutes of rambling, one document you’d actually show someone.
Transcription is macOS 26’s own, on this Mac; one claude -p pass makes the concise version. Audio, transcripts and document all land in .zero/memos/.
it’s barely even there.
14MB on disk. A window in 0.38s. A quarter of a gigabyte with four projects open. Your RAM goes to the work, not to the app it runs in.
Numbers below, method in BENCHMARKS.md, scripts in bench/ to run on your own machine.
Same machine, same project, both editors, three launches each, median reported. M3 Max · 36GB · macOS 26.5.1 · Cursor 3.15.6. In every graph: zero is the bright mark; the long grey one is Cursor.
And 5 files in the bundle, against 17,035 — 3,407× fewer.
Drawn to scale, by area. The bright square is the entire frontend.
Two different finish lines: a window on screen first, ready-to-work second. A cold zero puts its window up before a warm Cursor does — 0.38s against 1.14s.
MB of phys_footprint, one through four projects measured, the dashed part extended on Cursor’s own slope — a window per project, ~360MB and three processes each. zero opens a tab instead; its per-project cost is below its own noise floor, which is why its line won’t sit still.
The whole bundle is five files. There is nothing to update, nothing to sync, and nothing to disable.
Of one core, while doing nothing.
The one graph where longer is better. zero on a ProMotion display against WKWebView’s default 60fps clamp — Safari was the control, so the machine was never the limit.
Each keeps its own terminals, sidebar and files. Switching is instant, because nothing re-renders.
Full width, splits in any direction, no chrome. Buttons appear when the pointer comes looking.
Every worktree down the sidebar with its changes, staging and commit box.
Every uncommitted line gets a bar — in the gutter, beside the scrollbar, and up the file tree.
⌘P fuzzy-opens anything git admits to. ⌘⇧F searches in Rust,
quicker than ripgrep. ⌘-click jumps to a definition, and file.ts:42 in the
terminal opens on the line.
Projects, splits, tabs — restored. claude --continue does the rest.
An extension marketplace. A sign-in. A welcome tour. A chat panel you can’t close. Network code of any kind.
Apple Silicon only. macOS 26 only.
zero is purpose-built for exactly one platform. No Intel branch, no Electron, no compatibility ballast for a MacBook from 2017 — and it leans on macOS for everything macOS is already good at: the WebView, the transcriber, the fonts. Building for one machine instead of every machine is why the whole app is 14MB and why it opens in 0.38s.
brew install --cask zero-editor/tap/zero
Or download the dmg
and drag zero to Applications. Apple Silicon, macOS 26, git — nothing else.
The whole thing is open source on GitHub — 21,596 lines of MIT. Read it in an afternoon, or build it yourself in about a minute.