Microsoft announced: Today, we’re very excited to announce the open-source release of the Windows Subsystem for Linux. This is the result of a multiyear effort to prepare for this, and a great closure to the first ever issue raised on the Microsoft/WSL repo.
That means that the code that powers WSL is now available on GitHub at Microsoft/WSL and open sourced to the community! You can download WSL and build it from source, add new fixes and features and participate in WSL’s active development.
WSL was the first announced BUILD back in 2016 and first shipped with the Windows 10 Anniversary update.
At that time, WSL was based on a pico process provider, lxcore.sys, which enabled Windows to natively run ELF executables, and implement Linux sys calls inside the Windows kernel. This eventually became what we today know as “WSL 1”, which WSL still supports.
Over time it became clear that the best way to provide optimal compatibility with native Linux was to rely on the Linux kernel itself. WSL 2 was born, and first announced in 2019.
Bleeping Computer reported: Microsoft has open-sourced the Windows Subsystem for Linux (WSL), making its source code available in GitHub, except for a few components that are part of Windows.
This makes a milestone for a project that started as an experiment almost a decade ago but has grown to become a very popular tool in Windows.
It’s first release, WSL 1, utilized a compatibility layer that translated Linux system calls so they could communicate and work with the Windows NT kernel using a custom driver named lxcore.sys.
Now, at Microsoft Build 2025, the company has made WSL open source, including its command-line tools, background services, and Linux-side daemons used to start networking, launch other daemons, and set up port forwarding.
“WSL could never have been what it is today without its community. Even without access to WLS’s source code, people have been ablate make major contributions that lead to what WSL is now,” Microsoft’s Pierre Boulay shared in an announcement.
The Verge reported: Microsoft is making its Windows Subsystem for Linux (WSL) open-source today, opening up the code for community members to contribute to.
After launching WSL for Windows 10 nearly nine years ago, it has been a multiyear effort at Microsoft to open-source the feature that enables a Linux environment within Windows.
“It has been a consistent request from the developer community for some time now,” says Windows chief Pavan Davuluri in an interview with The Verge.
“It took a little bit of time, because we needed to refactor the operating system to allow WSL to live in a standalone capacity that then allowed us to open-source the project and be able to have developers go and make contributions and for us to ingest those into the Windows pipeline and ship it at scale.”