KAPPA OS — the portfolio of John Kappa, product designer in Melbourne

KAPPA OS is a product designer’s portfolio disguised as a miniature desktop operating system. It boots — with a progress bar and a POST line — into a desktop you can actually use: windows with traffic lights, a dock, a working file system, a Trash that remembers where things came from, undo, Spotlight search, keyboard shortcuts, spring-loaded folders and a screensaver. The work is filed on the desktop the way work is filed on a real machine, and you open it the way you would open it there. This summary exists because the desktop itself is drawn in the browser; the sections below describe everything the interface contains.

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About John Kappa

John Kappa is a product designer and builder based in Melbourne, Australia. His background is in branding, UX and web design, across more than two decades. Somewhere along the way the work turned from designing things for other people into making his own — tools, fonts, extensions, experiments. Things that solve a problem or scratch an itch, mostly his own itch.

He is now deep into AI: not the hype version, the practical, hands-on, what-can-we-actually-build-with-this version. He holds that AI doesn’t replace instinct so much as accelerate it, and that the best products are built by people who can think across the whole thing — brand, UX, code, copy, product. Chrome extensions, React apps, iOS and Android, full websites; some take an afternoon and some take months, and the size matters less than that something gets made.

On design itself he is brief about it: good design is mostly clarity and simplicity. Remove the noise, keep only what matters, make it feel obvious in hindsight. He is currently a Lead Product Designer and AI specialist, and is open to collaborators who care about craft and come at problems from unconventional angles. His personal site is johnkappa.com.

What is inside KAPPA OS

The desktop ships with folders for projects, experiments, photography and wallpapers, and a dock of applications. The design language is monochrome, flat and engineered, with colour only in small functional accents — apart from three surfaces that are deliberately physical objects rather than documents. Images dragged in from the host operating system land wherever they are dropped.

Projects

ClearSlate

Just a simple Links, Notes and Task tool

Role: Design & Build · Year: 2026 · Platform: Chrome Extension · Status: Live. Add to Chrome

Does it sync between machines? No. Everything stays in the browser it was written in, which keeps it fast and means there is no account to make.

Is there a paid tier? No. It does one small job and it does it for free.

Why replace the new tab page? Because it's the one surface you already look at dozens of times a day without deciding to.

Experiments

Smaller things, built and shipped:

Photography

Shot by John and shown in SNAP, the OS’s photography app, as a wall of uncropped pictures or a dome you turn.

Elsewhere on this site

Questions

Who is John Kappa?

A product designer and builder based in Melbourne, Australia, with more than twenty years across branding, UX and web design. He now works hands-on with AI — building tools and products rather than only designing them — and is currently a Lead Product Designer and AI specialist.

What is KAPPA OS?

John Kappa's portfolio, built as a miniature desktop operating system that runs in the browser. Rather than scrolling a page you boot into a desktop: open windows, drag files between folders, play music, run a terminal, browse photographs, change the wallpaper. The work is filed on the desktop the way work is filed on a real machine.

What can you do in KAPPA OS?

Open, move and resize windows; rename files and drag them between folders; use the Trash, Put Back and undo; search with Spotlight; read project case studies; browse photography as a WebGL wall or dome; play music in a skeuomorphic tape deck; run commands in a terminal; visit other sites in a period browser; strike a certificate plate for any name; play a game; set the wallpaper, theme and accent; and leave it alone long enough to reach a screensaver.

Is John Kappa available for work?

Yes. He is open to collaborators and to work that involves building something real — problems that are genuinely hard, approached from an unconventional angle.

What is KAPPA OS built with?

Next.js with the App Router, React, TypeScript and Tailwind CSS. The photography wall and dome are WebGL, by way of three.js. Every icon is an SVG path or CSS and every sound is synthesised at runtime — there are no image or audio assets in the interface itself.

Contact

KAPPA OS BETA

POST — CPU / MEM OK_