Microsoft Embraces Open Source with Windows Subsystem for Linux
In a significant move for developers and tech enthusiasts alike, Microsoft has announced the open-sourcing of the Windows Subsystem for Linux (WSL), a platform that has evolved considerably since its inception in 2016. Originally unveiled during the Windows 10 Anniversary Update, WSL was designed to enable Windows to run ELF executables natively through a compatibility layer, utilizing a pico process provider known as lxcore.sys.
While WSL provided a valuable tool for bridging the gap between Windows and Linux, it faced compatibility challenges that necessitated the implementation of a true Linux kernel. This led to the introduction of WSL2, which was made available to testers in 2019. By 2021, Microsoft recognized the need for a more agile approach, opting to remove the code from the Windows ecosystem to better align with the rapid pace of updates typical in the Linux community.
As we approach 2024 and the rollout of Windows 11 24H2, Microsoft has completed the transition to its new WSL package, moving away from the original WSL component that was bundled with Windows. This transition marks a pivotal moment in the platform’s development.
Although components of WSL2 have always been open source due to their reliance on a Linux kernel, Microsoft has now taken the bold step of making nearly all of the previously closed code available. “The code that powers WSL is now accessible on GitHub at Microsoft/WSL, open-sourced for the community,” the company announced, inviting developers to download, build from source, and contribute to the ongoing evolution of WSL.
However, for those hoping for access to the Windows kernel, the news is less promising. The kernel-side driver lxcore.sys, which supports WSL1, remains part of the Windows images and is not open-sourced at this time. The same holds true for 9rdr.sys and p9np.dll, which facilitate file system redirection between Windows and Linux via wsl.localhost.
Microsoft acknowledged the vital role of the community in shaping WSL, stating, “WSL could never have been what it is today without its community.” However, the company has yet to clarify how the project will be managed moving forward. While the invitation for direct code contributions is a welcome development, clarity on how these contributions will be integrated into the project’s future direction remains essential.
Inquiries have been made regarding the establishment of a steering committee for the newly open-sourced WSL or whether it will continue to be guided by Microsoft’s leadership. Additionally, questions linger about the implications for Windows Server workloads. As the tech community awaits further details, the excitement surrounding this open-source initiative continues to grow.
