NSL: Bringing WSL-style Virtualization to Linux

Philosophy: Keep the host atomic.

NSL (NSpawn Subsystem for Linux) provides Linux users with the same experience Windows users get with WSL: the ability to run persistent, independent Linux machines directly on a Linux host.

Each instance is a complete distribution, maintaining its own unique services and package sets. These operate as systemd-nspawn containers housed within a lightweight VM, launching automatically upon use and integrating seamlessly with your local filesystem.

🛠️ Getting Started & Usage

To begin, install nsl and initialize your first environment:

# Create a new Debian 13 machine
nsl create debian --distro debian:13 

# Enter the default machine's login shell in the current directory
nsl 

# Execute a specific command and return its exit status
nsl run make test

The Machine Experience

When you launch a machine, you get a fully functional distro in a single command. Your environment is configured for convenience:

• Identity: Your username, GID, and UID are preserved.
• Privileges: You are granted passwordless sudo access.
• File Access: Your host's $HOME, /mnt, and /run/media/USER are mapped to /mnt/host inside the container.
• Networking: Any server running inside a machine is accessible on the host via 127.0.0.1 at the same port.

🏗️ Architecture & Security

NSL balances convenience with strict isolation. The general flow is as follows:

Trust and Isolation

For software that is untrusted, you can use the --isolated flag. This creates a dedicated VM that lacks access to:

1. Host files
2. The desktop environment
3. Host-level actions

Note: NSL is non-intrusive; it does not modify your host's sudoers, device permissions, or groups, nor does it install any packages on the host system.

📦 Supported Distributions

NSL provides seven signed distributions, rebuilt weekly and verified via the Frostyard publishing pipeline:

📖 Navigation Guide

• 01 Get Started: Verify host compatibility, install the tool, and deploy your first machine.
• 02 Architecture: Deep dive into the VM structure and host interaction boundaries.
• 03 Reference: Explore every available command, nsl.conf settings, and image list.

⚙️ Technical Specifications

The current stable version is defined as $v \ge 0.4.0$. v0.3.0 and earlier versions are now considered retired prototypes.

The software was validated on the following environment: