Microsoft has opened the source code of Windows Subsystem for Linux
By ForGeeks Microsoft announced that the source code for the Windows Subsystem for Linux (WSL) was made open source at the Build 2025 conference. Most of the components are now available on GitHub, except for those closely related to the Windows kernel.
WSL began as an experiment nearly a decade ago and over time has become one of the most sought-after tools for Windows developers. Its discovery was an important milestone in the history of the project.
The WSL was first introduced at Build 2016 and was part of the Windows 10 Anniversary Update. The first version, WSL 1, implemented Linux compatibility through a system call translation layer for the Windows kernel, using the lxcore.sys driver.
In 2019, Microsoft released WSL 2 – with a full Linux kernel running inside a virtual machine. The new architecture provided significant performance gains, GPU and systemd support, and the ability to run graphical applications.
The company now publishes source code for key components: command-line utilities (wsl.exe and wslg.exe), background services (wslservice.exe), and Linux-side daemons for networking, process startup, and port forwarding.
Microsoft spokesman Pierre Boulet said the community has played a key role in the development of WSL, despite the code’s closed nature:
“Even without access to the source code, people have been making valuable contributions to WSL. Now that the project is open source, we look forward to hearing more ideas, improvements, and solutions from developers around the world.”
Some components will remain closed because they are part of Windows. These include the lxcore.sys driver for WSL 1 and the P9rdr.sys and p9np.dll modules, which are responsible for file redirection to «\wsl.localhost».
Opening the WSL source code allows developers to explore the internals of the subsystem, build it themselves, and make changes. Microsoft expects this to help accelerate the technology’s development and get the community more involved.
The story Microsoft opens source code for Windows Subsystem for Linux was first published at ITZine.ru.
