The year of Linux on the desktop is finally upon us. Microsoft tried to make it happen in 2017 when it released Windows Subsystem for Linux. Back then, Microsoft wrote a wrapper for Linux system calls that translated those calls into Windows NT kernel functions. It works, but it's not very fast and many apps won't run. Microsoft knows this, and yesterday at the annual Build conference, the Windows maker announced the second iteration of Windows Subsystem for Linux.
This time around, WSL will ship with a Linux kernel that runs in a lightweight virtual machine (VM). However, Windows Developer Platform head Craig Loewen promises that instead of working like a traditional VM running in its own isolated environment, the Linux subsystem will boot quickly, use few resources, and not require any VM management. Loewen says that this is the first time Windows will ship with a Linux kernel. Since WSL2 has its own kernel, Loewen says that many more apps will run on Windows than would run in the previous iteration. Microsoft expects WSL2 Insider releases to happen near the end of June.
Speaking of the new kernel, a companion piece by Microsoft Linux Systems Group program manager Jack Hammons dives into the new subsystem's core components. WSL2's kernel is initially based version 4.19, a long-term support (LTS) release. According to Loewen, the company will continue contributing to the Linux kernel. He says that Microsoft employs a "growing number" of Linux contributors. Hammons also expects that all changes Microsoft makes to the kernel will make their way upstream from WSL2 back to the GNU Linux kernel project.
To accompany WSL2, Microsoft has also announced a new Windows Terminal application. Rather than use good ol' cmd.exe for DOS-style commands, PowerShell for its scripting language, and a third terminal app for WSL, Windows Terminal will allow users to mix-and-match all three technologies in a single app with a tabbed interface. Windows Terminal appears to be a front-end for existing applications, and program manager Kayla Cinnamon says that existing apps aren't going anywhere. Like many of Microsoft's other recent releases, Windows Terminal is an open-source project. Interested gerbils can grab the source and build it for themselves from its GitHub repository.