# 🏛️ NexusOS Architecture Overview

> "Freedom does not begin with GPL. Sometimes it begins with understanding."  
> — *NexusOS Manifest*

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## 📌 Purpose

NexusOS is not just a Linux distribution.
It is a **declarative operating system architecture**, designed for:
- **developer sovereignty**  
- **runtime reproducibility**  
- and **strategic modularity**  

...without compromising commercial usability or ideological clarity.

This document outlines the **strategic multi-core foundation** of the NexusOS ecosystem, including its variant roles, licensing philosophy, and system layering model.

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## 🧱 Primary Pillar: NexusOS (Mainline)

**Codename:** `NexusOS`
**Foundation:** Hardened Linux Kernel + musl + jemalloc  
**Userspace:** GNU-free (Toybox, sbase, etc.)  
**Tooling:** `nip` + `.npk` + `NimPak` (Nim DSL for package/build/runtime)  
**Target:** Workstations, modern desktops, servers, developer clouds

### Why This Path?
- ✅ Full hardware support (GPU, peripherals, drivers)
- ✅ Seamless Wayland & Cosmic Desktop integration
- ✅ Maximum compatibility with containers and cloud runtimes
- ✅ Complete control of userspace and package/runtime layering

> _This is the "flagship" system — pragmatic, reproducible, fast, and modular._

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## ⚫ Variant 1: NexusBSD

**Codename:** `NexusBSD`  
**Foundation:** DragonflyBSD Kernel  
**Userspace:** musl + Toybox + NimPak  
**Target:** Proprietary appliances, hardened edge devices, low-IO cloud clusters  
**License Model:** Fully BSD-compatible + ACUL dual-license  

### Why DragonflyBSD?
- 💡 Linux binary compatibility (via Linuxulator)
- 🧊 Superior SMP and filesystem (HAMMER2)
- 🚫 No GPL contamination at the kernel level
- 🔒 Ideal for commercial closed-box systems needing GPL-free stack

> _This is the "pure BSD" variant — designed for deterministic, licensed appliance deployment._

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## 🔴 Variant 2: NexusSafe-Core

**Codename:** `NexusSafeCore`  
**Foundation:** Redox OS, Theseus OS, or custom Rust kernel  
**Userspace:** Nim-only or custom microprofile  
**Target:** Formal verification, medical/industrial systems, academic security research  

### Why Explore This?
- 🦀 Memory-safe kernel and driver model
- ✨ Compile-time system understanding (Theseus-style)
- 🔬 Ideal for long-term evolution of verifiable infrastructure

> _This is the "research kernel" — not for MVP, but a beacon for the future._

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## 🟣 Variant 3: NexusUnikernel

**Codename:** `NexusUnikernel`  
**Foundation:** Unikernel toolchain (e.g., rumpkernel, OSv)  
**Tooling:** `nip build <pkg> --target=unikernel`  
**Target:** Cloud functions, edge microservices, serverless workloads

### What Makes This Strategic?
- ⚡ Generates bootable, single-purpose artifacts
- 🔐 Minimal attack surface, no userspace
- 🤖 Fully automated reproducible builds (via `.npk` + runtime logs)

> _This is the "application-as-OS" path — built entirely via Nexus tooling for next-gen cloud runtimes._

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## 🔐 License Philosophy: MIT + ACUL

NexusOS is dual-licensed:

- **MIT License:** for open-source, educational, and non-commercial use
- **ACUL (Anomaly Commercial Use License):** for proprietary or closed-source usage

ACUL requires:
- Attribution
- Reproducibility via `.npk` logs
- Active Nexus Foundation membership (Bronze/Silver/Gold)

> _This dual license strategy enables wide adoption **without copyleft lock-in**, while preserving build-time accountability and ecosystem funding._

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## 🧩 NexusOS Layering Model

| Layer             | libc   | Allocator     | Purpose                                 |
|------------------|--------|---------------|-----------------------------------------|
| 🧱 Core/Base      | musl   | internal      | Init, shell, recovery tools             |
| 🧰 App Layer      | musl   | jemalloc      | CLI apps, system tools, servers         |
| 🖥 Desktop Layer  | glibc  | glibc malloc  | KDE, Wayland, Cosmic, GUI apps          |
| ⚙️ systemd Layer   | glibc  | jemalloc      | systemd, journald, services             |

Control of these layers is done **declaratively** via `.npk.yaml` recipes and enforced during build/install with the `nip` engine.

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## 📦 Variant Summary Table

| Variant         | Kernel        | License Model    | Role                            | Status        |
|----------------|---------------|------------------|----------------------------------|---------------|
| **NexusOS**     | Linux         | MIT + ACUL       | Mainline Desktop/Server OS      | MVP Target ✅  |
| **NexusBSD**    | DragonflyBSD  | BSD + ACUL       | Proprietary edge/server variant | Planned       |
| **NexusSafeCore** | Redox/Theseus | Apache/MIT        | Verified secure kernel R&D      | Research Phase |
| **NexusUnikernel** | Any (via toolchain) | Embedded via ACUL | App-as-OS build target          | Phase 4–5     |

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## 🚀 Strategic Direction

We are not building "just another distro."

We are designing:

- A verifiable OS
- A programmable system
- A modular foundation
- A reproducibility-driven ecosystem
- A licensing and packaging architecture **fit for open infrastructure and commercial clarity**

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## 📜 Appendix: Licensing Badge for ACUL

```markdown
[![ACUL Licensed](https://img.shields.io/badge/License-ACUL-blue.svg)](https://nexus.foundation/membership)
