LiberNT

A free NT operating system

Built out of love for the NT architecture. Windows® 11 compatible, for amd64, arm64 and riscv64.

_{The LiberNT desktop on arm64, from build nt10.0-043-2555 in QEMU}

LiberNT is a free NT operating system. The name says it: liber is Latin for free. It targets Windows® 11 compatibility, with room for freestyle and experimental features.

LiberNT brings extensive work on kernel-space components and drivers, aimed at stability and modern hardware, and it focuses on 64-bit platforms: amd64, arm64 and riscv64.

Our goal is a system that stays maintainable in the long run: stable, reliable and efficient, running on embedded devices too, and able to support every feature a modern operating system should have.

• What LiberNT Includes
• Supported Platforms
• Getting Started
  • Step 1: Download a Build
  • Step 2: Boot It
  • Step 3: Install LiberNT
• Building LiberNT Yourself
• Build Hosts
• Project Structure
• Contributing
• Use of AI
• License
• About

LiberNT brings modern hardware and platforms to the NT architecture.

Release builds also include PowerPC images.

Every build on the Releases page comes as one ZIP file per image and architecture:

The quickest way to try LiberNT is the preinstalled disk:

1. Unzip LiberNT.img (or LiberNT.vhd)
2. Start it in a virtual machine such as QEMU, or use the VHD in VirtualBox or a Hyper-V Generation 1 virtual machine. Hyper-V Generation 2 takes only LiberNT.vhdx, with Secure Boot turned off
3. Or write LiberNT.img to a USB drive or an SD card and boot the machine from it. It boots with UEFI or BIOS

Boot bootcd.iso in a virtual machine or on a PC, and follow the instructions of LiberNT Setup.

The preinstalled disk also carries LiberNT Setup. Run C:\<architecture>\libernt.exe, for example C:\arm64\libernt.exe, to install LiberNT on another disk from the running system.

See INSTALL.md for the full installation guide.

LiberNT builds with RosBE, a cross-build toolchain. The steps below work on Linux and macOS, and on Windows through WSL2.

You need Git, CMake, Ninja and a C/C++ compiler for your own machine. RosBE adds the compilers that build LiberNT.

curl -fsSL https://raw.githubusercontent.com/LiberNT/libernt-build-toolchain/main/rosbe-unix-bootstrap.sh | sh

git clone https://github.com/LiberNT/LiberNT.git
cd LiberNT

./configure.sh

With no options, this sets up an AMD64 Debug build with Clang in the folder output-Clang-amd64-debug. The folder name always follows the pattern output-<compiler>-<architecture>-<debug|release>.

For example:

./configure.sh -a arm64              # ARM64 Debug build with Clang
./configure.sh -a i386 --gcc         # 32-bit x86 build with GCC
./configure.sh -a amd64 --release    # optimized AMD64 build

For a more personalized build, add menuconfig:

./configure.sh menuconfig

It opens a menu, much like the Linux kernel's, where you choose the target, compiler and build type, and switch features on or off: code generation and tuning, graphics driver model and Mesa, WoW64 and FEX, kernel debugging, test runs and more. Press ? on any option for help, S to save and Q to quit. Your choices are saved in the output folder and used every time you configure it again.

Go to the output folder and run Ninja with the target you want:

cd output-Clang-amd64-debug
ninja liberntimg

Each target builds everything it needs first, and the files are written to the output folder.

On every host, install Git, CMake, Ninja, Flex and Bison from your package manager. RosBE provides only the cross compilers. Prebuilt toolchains live in LiberNT/libernt-build-toolchain.

LiberNT/
├── base/            # Applications, services, setup and the shell
├── boot/            # FreeLoader, boot data and boot images
├── bootloader/      # Boot manager, Windows loader, UEFI and Open Firmware support
├── dll/             # User-mode DLLs, including ntdll and the Win32 libraries
├── drivers/         # Kernel-mode drivers: buses, storage, file systems, network, input and more
├── hal/             # Hardware abstraction layers for x86, Arm, Arm64, PowerPC and RISC-V
├── media/           # Fonts, themes, INF files, sounds and branding
├── modules/         # Optional applications, tests and wallpapers
├── ntoskrnl/        # The NT kernel and executive
├── sdk/             # Headers, libraries and build tools
├── submodules/      # Recipes and patches for external components
├── subsystems/      # CSRSS and the Windows subsystem
├── win32ss/         # win32k, USER, GDI and display drivers
├── configure.sh     # Sets up a build on Linux, macOS and WSL2
└── configure.cmd    # Sets up a build on Windows

Report bugs and suggest features in Issues, and find guides and notes in the Wiki.

See CONTRIBUTING.md and PULL_REQUEST_MANAGEMENT.md. If you're planning a larger change, ask in Issues or on Discord first.

We want to make it clear: AI is part of how LiberNT is built. It helps us review and write code, and everything it writes is then reviewed by a human. Before anything reaches the main branch, a person runs and validates the end-to-end tests. We care about this project too much to let a regression slip through.

It also helps us read documentation, extract definitions and fix bugs. For any given bug, it compares what the official Microsoft Learn documentation says with what our function actually does, so we can see exactly where our behavior differs.

Like any other tool, AI is there to help us achieve our goals. It follows the same rules we hold ourselves to, set out in AGENTS.md:

• We build from the Windows SDK and WDK headers, Windows 11 public symbols, Microsoft documentation and black-box runs on Windows 11.
• We stay clean-room: we never transcribe disassembled or decompiled Windows code, and we never copy GPL code from Linux.
• A fix is only a fix once we have seen it work in a real boot or test run. Once tests pass, a future CI will keep them passing and preserve our overall progress.
• We compare our test results check by check with the same tests run on Windows 11.

LiberNT is licensed under the GNU GPL 3.0. Code inherited from other projects keeps the licence stated in its file headers, most of it GPL 2.0 or later. The GPL 2.0, LGPL 2.1 and BSD texts those files refer to are in COPYING2, COPYING.LIB and COPYING.ARM.

The changes made in LiberNT are Copyright © 2026 the LiberNT contributors. Inherited and third-party code keeps the copyright notices of its authors. See CREDITS.md.

LiberNT is an independent project. It is not affiliated with, endorsed by or sponsored by Microsoft. Windows® is a registered trademark of Microsoft Corporation.

LiberNT is built by the LiberNT contributors, started and maintained by Ahmed Arif.

• Visit the LiberNT organization
• Website
• Download the latest build
• Wiki
• Chat on Discord or Matrix