The fact that Microsoft released Windows Subsystem for Linux (WSL) as an open-source environment was a big news in itself. Publication on the codebase WSL was officially published on GitHub during the Build 2025 event when Microsoft authorized users to download and make changes. In an official statement, Microsoft revealed that WSL codebase is now hosted in the GitHub and can be accessed by the community. WSL development model has undergone a paradigm shift as Microsoft has given the freedom to directly add the fix and feature and improvements to the platform to the community after several years of in-house development.

Microsoft used Build 2025 to flip two big switches at once:

• The entire Windows Subsystem for Linux code-base is now MIT-licensed on GitHub — CLI tools, background services and the user-mode pieces that power WSLg are all there for you to clone, hack and ship patches. (blogs.windows.com, theverge.com)
• The same drop bumps the Store package to version 3.0 (nick-named “WSL 3”). Besides the source release, 3.0 promotes last year’s experimental work — mirrored networking, automatic memory/disk reclaim, a Zero-Trust security model and a forthcoming Settings GUI — to stable defaults. (devblogs.microsoft.com, bleepingcomputer.com, neowin.net)

We can say that WSL 3 is faster, easier to manage and safer than WSL 2 that first brought a real Linux kernel to Windows. This transition did not take place once—it marks the latest milestone in a steady evolution for WSL. This is how WSL has grown over time:

• WSL 1 (2016): During tis period, WSL was debuted with the Windows 10 Anniversary Update, the original version of WSL was simply a translation layer that enabled Windows to do so-called headless execution of Linux ELF binaries. It made use of Linux system calls in a special component (lxcore.sys) in the Windows NT kernel, a so-called “pico” process provider. This provided fundamental support of bash and the typical command-line tools, although compatibility and performance were poor since there was a translation overhead to convert between Linux and Windows.
• WSL 2 (2019): Microsoft thoroughly overhauled WSL, when they introduced WSL 2 with windows 10 version 2004. The WSL 2 emulated a real Linux kernel within a lightweight Hyper-V based virtual machine, as opposed to translating system calls. Most of the advantages offered by this upgrade were significant; full compatibility with Linux system calls and an enormous performance gain. Today, most Linux tasks such as compiling software or using a web server ran almost similarly on Windows compared to running native on Linux. Moreover, Microsoft mentions that WSL 2 usually consumes fewer resources in comparison to conventional virtual machines, yet it also allows you to access Windows and Linux tools on equal files simultaneously.
• WSLg, GPU and Systemd (2020–2022) – As WSL’s community grew, Microsoft added big new features. GPU compute support (for AI/ML) and WSLg (the Windows Subsystem for Linux GUI) allow users to run Linux graphical applications on Windows. systemd support was also introduced. Late 2022 WSL was dropped out of the Windows image and being delivered through Microsoft Store as a seperate product called its own “WSL package”, which could be updated regardless of the Windows update schedule. The first build to transition the user to this new Store-based WSL was Windows 11 24H2.)

In general, WSL has matured steadily into a capable Linux layer on Windows until today it has become officially WSL 3, an open-source project.

WSL 3 and Open Source

In WSL 3, the most important development is that of transparency: the major parts of WSL are on GitHub. As Microsoft stated, “now it is possible to download WSL and even build on your own as well as to add new fixes and features and contribute to the active WSL development.” The GitHub repository (microsoft/WSL) now includes the key Windows-side components like wsl.exe, wslconfig.exe, and wslg.exe, along with the core WSL service (wslservice.exe). It likewise offers Linux-side initialization scripts and daemon processes that are performed in the virtual machine. To be more specific, essentially the whole WSL infrastructure, including the tools to enable WSL on Windows, as well as the underlying background services running in the VM are now completely open source and crowd-sourcable.

Importantly, it allows direct community investments. According to one TechRadar headline, “In open-sourcing WSL, Microsoft has opened it to direct contributions, feature development and bug fixes by the wider community”. The change was even confirmed by Microsoft own team of engineers: WSL could never be what it is today without the community behind it and we are very excited to see what WSL will become now that the community is able to contribute in the form of actual code. In practice, this is the ability that developers today have, to make a GitHub pull request to upgrade networking, file sharing, performance or to introduce a feature enhancement (which is how open-source projects typically operate)..

Majority of the components in the WSL have become open-source and only few drivers in the Windows (Windows-specific drivers) are yet to be closed. As an example, the WSL1 kernel driver lxcore.sys  (which handled syscall translation in WSL 1) and the Plan9 network redirector (P9rdr.sys, p9np.dll) are still proprietary. These closed artifacts have an impact to the legacy mode only because WSL 2 architecture no longer utilizes lxcore.sys. Otherwise, WSL 3 belongs to the community.

Windows and linux gear up harmoniously in the background given the WSL configuration. On the Windows side, you have a very important service that is called wslservice.exe which starts the operating system to start the virtual machine; it actually keeps your Linux distros in tab. In the meantime, convenient services such as wsl.exe and wslconfig.exe allow you to simply execute the command, or adjust the settings to make everything the way you prefer. Within the linux system, a lightweight init system (and other daemons) is responsible in doing important things to WSL, including networking, port forwarding, and execution of the file server that provides file sharing capability between the windows and linux filesystems. This scheme is represented in the above diagram. All these components are open to inspection and enhancement by developers with WSL 3 being free of charge. As an example, now engineers can learn or modify how wslservice.exe boots the VM or how files are shared by Plan9 server.

In addition to being more transparent, WSL 3 keeps all of the performance and compatibility benefits of WSL 2. It means that WSL 3 will have the same version of the Linux kernel in the hypervisor, resulting in WSL 3 having the same compatibility of system calls as Linux. According to Microsoft, WSL is a task that has less system resources requirement than a full virtual machine, i.e. it boots up with high speed and memory resource scalability. In reality, developers discover that most build tools on Linux, web servers, databases, and other programs installed in WSL perform nearly as quickly as on native Linux.

Another visible enhancement is GUI and hardware support. WSLg – already open-sourced – provides a Wayland/X server so graphical Linux apps can display on the Windows desktop. For example, developers are able to launch Linux-based editors, web browsers, or visualization applications straight from Windows. WSL 2 also offers GPU acceleration (supporting CUDA and DirectML), allowing machine learning and high-performance computing tasks to utilize the GPU from within Linux applications. Notably, both the WSLg component and the specialized WSL2 Linux kernel have already been made available on GitHub, highlighting Microsoft’s dedication to providing a robust and fully integrated experience.

What’s New and What’s Next

By open-sourcing WSL 3, Microsoft isn’t just releasing code – it’s inviting innovation. We expect several benefits and use cases for developers:

• Community-driven enhancements. Now anyone can dig into WSL’s code. For instance, developers now have the opportunity to suggest improvements to WSL’s networking layer, contribute support for new hardware features like enhanced USB passthrough, or strengthen security by reviewing and auditing the source code. Long-standing feature requests – perhaps slow to arrive in previous closed development – can now be addressed via GitHub pull requests. In short, WSL can evolve faster and in more directions than if Microsoft tried to tackle everything internally.
• Cross-platform development. Many developers need to target both Windows and Linux (for example, web backends on Linux servers, or cloud services). WSL makes it trivial to build and test Linux applications on a Windows machine. With WSL 3 open-source, Windows becomes an even stronger choice: a developer can run a Linux-based toolchain or container inside WSL, debug it, and iterate – all without leaving Windows. Likewise, Windows-first devs can more easily pick up Linux tooling knowing it’s fully supported.
• DevOps and CI/CD integration. . Linux containers can be used in automated build pipeline processes. Unlike with the previous releases, the same scripts and Docker images can be run natively using Windows systems, including build servers, with WSL 3. As another example, a Windows server may use WSL to create a Linux container to test in, without requiring it to create an altogether distinct virtual machine, or port to a distinct host. Teams can also customize the integration where necessary, which becomes possible now that WSL is open source e.g. customizing the interaction between Docker Desktop and WSL under the hood.
• System-level and hardware tooling. Most system programmers tend to use special tools such as debuggers, cross-compilers and embedded Linux SDKs whose main features were previously exclusive to Linux. That limitation disappears with WSL 3, these tools have now the possibility to run on Windows and have all their features. Not only that, kernel hackers may even test with different Linux kernels or drivers within the WSL VM since the Linux kernel is open. WSL is also completely equipped to deal with GPU-accelerated computing, such as to train AI or to run simulations, and opening it up to open-source code in the future might enable enhanced performance and compatibility with more hardware in the future.
• Open-sourcing WSL also brings greater collaboration and transparency. It facilitates trust, because the WSL code can be reviewed by an IT and security team to see whether it presents vulnerability or compliance problems. This step places WSL on a par with other cross-development instruments that are open-source based, which will make the developers who use (and develop) open-source software feel assured, as they can see how WSL functions inside, meaning inspect and alter its functioning.

Why This Matters

In our view, Microsoft’s move to open-source WSL 3 is a watershed moment for the Windows–Linux development landscape. It recognizes that today’s developers expect openness and interoperability. As Microsoft itself notes, this change “facilitates collaboration among WSL users, enabling them to engage in issue resolution and learn together as a community”. Instead of a closed, proprietary subsystem, WSL 3 becomes a community project.

This has strategic impact. Windows now offers a best-of-both-worlds environment: you get the Windows ecosystem and tooling and a first-class Linux environment, without compromise. For example, a web developer can run Apache or Nginx in WSL while editing code with Visual Studio on Windows, and debug everything seamlessly. In the past, achieving this might have required a Linux VM or dual-boot – both clunkier solutions. Now it’s built-in and crowd-sourced.

We also expect productivity gains. Because the community can contribute, common frustrations (like subtle compatibility quirks or performance bottlenecks) could be fixed more quickly. The modularity of WSL means even novel use cases – say, custom Linux distros for specific devices – can be supported if someone in the community builds them. Windows effectively gains the agility of open-source development.

Finally, there’s a symbolic message: Microsoft doubling down on open source sends a signal of respect toward the Linux developer community. Over the past decade Microsoft has embraced many open-source technologies (joining the Linux Foundation, open-sourcing .NET, acquiring GitHub, etc.). Making WSL itself open source may be the most emblematic move yet. It shows that Microsoft views the success of Windows as linked to the success of Linux – a profound shift from the “Linux is the enemy” era.

To conclude, WSL 3: Open-Sourced is not only another version, it is a pivot. Windows developers have never been able to look so deeply into the Linux layer below them and Linux-knowledgeable developers have justification in looking at Windows as a friendly platform. Looking forward to the next few months, we look forward to the Windows and Linux community working together to create new functionality and performance gains to WSL. This implies that the Windows Subsystem for Linux will evolve faster and in creative directions we cannot even imagine and this will bring a new dawn to cross-platform development as far as developers are concerned.

Key Points:

• WSL previously developed on syscall translation (WSL1), it now provides a full Linux virtual machine (WSL2) with support on GPU/ GUI.
• In 2025, Microsoft opened a majority of WSL as the open-source project, putting the code on GitHub to embrace community contributions.
• Technical nodes Ideally, its hybrid architecture (it contained both Windows and Linux components), nearly native performance and powerful support of Linux GUIs (WSLg) qualify as highlights.
• WSL is now open source, making it easier to do cross-platform development with Windows and accelerate DevOps by having the ability to customize at the system-level tools commonly built on Windows.
• The step is another indicator of the growing Windows and Linux relationship and of the continued developer-focused insight and open cooperation in Microsoft

Run Linux & full-fledged GUI apps on Windows with the brand-new, open-source release

Because WSL is now an app, it updates on its own cadence — no Insider build required — but you must be on a supported OS build first. (blogs.windows.com)

Open PowerShell as Administrator and run:

# Fresh install: pulls the WSL 3 package, kernel and WSLg 
wsl --install -d Ubuntu

Already have WSL? Two lines get you to 3.0:

wsl --update      # downloads WSL 3.x
wsl --shutdown    # restarts the lightweight VM
``` :contentReference[oaicite:3]{index=3}  

---

## 3 — Verify you’re *really* on WSL 3  

```powershell
wsl --version     # shows WSL 3.x in the first line
wsl --list --verbose

If a distro still shows Version 1, convert it:

wsl --set-version <distro> 2   # WSL 3 builds on the 2-series architecture
``` :contentReference[oaicite:4]{index=4}  

---

## 4 — Update your GPU driver  

* **NVIDIA:** install the latest CUDA-enabled Windows driver.  
* **AMD / Intel:** grab the newest WHQL graphics package.  

The host exposes a *virtual* GPU to Linux, so **don’t install a Linux-side driver** — everything 3-D, Wayland and VA-API just works. :contentReference[oaicite:5]{index=5}  

---

## 5 — Install your first Linux GUI apps  

Inside your distro shell:

```bash
sudo apt update
sudo apt install gedit gimp vlc nautilus -y       # examples

WSLg sideloads each app into the Start-menu (and taskbar pin) automatically. Launch from Windows or run gedit & in the terminal. (devblogs.microsoft.com)

1. Blank windows or crashes → make sure you’re on WSL 3 and sudo apt full-upgrade.
2. libGL errors → outdated Windows GPU driver.
3. No audio → look for “PulseAudio (WSLg)” in Sound ► Output; if missing, wsl --shutdown.
4. Weird localhost mapping → remember: localhost from Linux → Windows; use wsl.localhost to reach Linux from Windows.

Microsoft’s engineers have hinted that the only closed pieces left (legacy WSL 1 driver and Plan 9 redirector) may follow suit, and that the Settings GUI plus Dev Home hooks will hit the main channel “later this year.” Meanwhile, the open-source repo is already accepting pull-requests — so if you’ve ever wanted to fix that one WSL quirk, now’s your chance. (blogs.windows.com, theverge.com)