SmileyOS: A Real Operating System Built with Cursor AI

A few months ago, Cursor posted a video showing how one of your team members created an “operating system” using vibe coding. It was actually a web app mimicking an OS—a clever bait-and-switch that got me thinking: “What if I built a real one?”

I accepted the challenge. Starting with Cursor’s cheapest subscription, I spent one month and nearly €3,000 to create SmileyOS—a fully functional operating system that boots on real hardware, supports multiple architectures (x86/32-bit, Raspberry Pi, RISC-V), and contains almost 100,000 lines of Rust code generated entirely by Cursor and Claude Opus 4.5 Max.

What is SmileyOS?

SmileyOS is a bare-metal educational operating system designed to teach kids ages 8-13 programming and computer skills. It’s written entirely in Rust and provides a safe, offline environment where children can learn to code, use a real terminal, and build foundational skills for software development.

Key Features

:desktop_computer: Modern Desktop: macOS-style menu bar, side dock for multitasking, window management, theme system

:laptop: Real Terminal: Command history, tab autocomplete, 40+ built-in commands (ls, cat, mkdir, cd, cp, mv, find, ps, kill, etc.)

:books: Smilium Programming Language: Custom language I created with three modes:

  • @shell - Text-based programs

  • @game - Visual game development with sprites

  • @app - GUI applications

Includes a built-in IDE with syntax highlighting, tab autocomplete, and 26 progressive programming lessons. Kids can write and run programs without rebuilding the OS.

:video_game: Apps & Games: Text Editor, Calculator, File Manager, Paint, Sprite Editor, Snake, Breakout, Whack-a-Mole, Type Attack, and more

:floppy_disk: Full OS Features: Multitasking, process management, file system with persistence, USB mouse support, SD card storage, network drivers

The Numbers

  • 1 month of development

  • ~€3,000 in AI subscriptions

  • ~100,000 lines of Rust code

  • Real hardware - boots on actual devices (tested on Dell Inspiron 910)

  • Multiple architectures - i686 fully working, abstraction for x86_64, ARM64, RISC-V

Every component—from the bootloader to the graphics stack, from the file system to the programming language interpreter—was built with Cursor AI.

Videos & Demo

You can find all development process videos on my YouTube channel. Most are in Macedonian (my native language), but I’m recording a comprehensive English demo video showcasing SmileyOS v1.7’s latest features, which will be posted soon.

Support & Sponsorship

If you want to support the project, you can donate via [Buy Me a Coffee link].

If Cursor is interested in sponsoring this project, please reach out! I’m planning to release the OS with full learning materials (5-6 printed books) and would love to partner with Cursor to make this educational platform available to kids worldwide.

This project proves that Cursor can help build complex, real-world systems—not just web apps. It’s a complete educational platform with a custom programming language, IDE, and learning materials, all built with AI assistance.

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