Yes, you did just read that heading correctly! Microsoft will be shipping a real Linux kernel with Windows that will make full system call compatibility possible. This isn’t the first time Microsoft has shipped a Linux kernel. In the past, Microsoft introduced Linux-based OS for datacenter network switches and a Linux-based microcontroller OS that it built for its Azure Sphere secure embedded service.
This release will improve Windows Subsystem for Linux (WSL) by unveiling the WSL 2. WSL 2 is a new version of the architecture that powers the Windows Subsystem for Linux to run ELF64 Linux binaries on Windows. This new architecture changes how these Linux binaries interact with Windows and computer’s hardware, but still provides the same user experience as in WSL 1. The first release will be based on version 4.19, the latest stable Linux release, and will keep up with each stable release going forward.
Architectural changes in WSL 2
WSL 2 uses the latest Virtualization technology to run its Linux kernel inside of a lightweight utility virtual machine (VM). But this is different than the traditional VM. This virtualization is not slow to boot up like normal and tradition virtualization. WSL 2 will give all the remarkable benefits of WSL 1 better integration between Windows and Linux and extremely fast boot times, small resource footprint.
But How Fast Is WSL 2?
Well, according to Microsoft “The actual speed increase will depend on which app you’re running and how it is interacting with the file system. Initial tests that we’ve run have WSL 2 running up to 20x faster compared to WSL 1 when unpacking a zipped tarball, and around 2-5x faster when using git clone, npm install and cmake on various projects”
The kernel will be open source. After the release of WSL 2 in Windows Insider, instructions for creating own WSL kernel will be available on Github. Earlier Microsoft also announced Windows Terminal command line app. WSL 2 will roll out to Windows Insiders by the end of June 2019.