Microsoft will start shipping a full Linux kernel inside Windows 10. According to program manager Jack Hammons, this summer, the company will include a custom version of Linux “to underpin the newest version of the Windows Subsystem for Linux (WSL).”

Initially, the kernel will be based on the version 4.9 of the most recent long-term stable release of the open-source operating system. However, the company says that eventually it’ll be rebased at the “designation of new long-term stable releases” to make that the WSL kernel always includes the latest Linux features and changes.

Similar to the version of WSL, Windows Subsystem for Linux 2 won’t offer any userspace binaries. “Instead, the Microsoft kernel will interface with a userspace selected by the user” through installation using the Microsoft Store.

It’s a significant change for the company as this will be the first time that the Linux kernel will be a native element of Windows 10.

The new approach will also improve the performance and compatibility of the current subsystem for Linux. In addition, the company says that the custom kernel will receive updates through Windows Update, and it’ll be open-source to allow developers to add their own changes.

Like the first version of WSL, the second version will use a virtualized environment, but Microsoft promises that it’ll be up to 20 times faster, won’t use a lot of system resources, and the experience will be the same as version one.

Although Microsoft isn’t sharing the exact release date, it’s expected for Windows 10 to ship with a custom version of Linux during the development of the 19H2 update.

Alongside the Linux integration into Windows 10, Microsoft recently announced a new Windows Terminal app designed specifically to run multiple command line environments, such as PowerShell, Command Prompt, and Linux, using a tabbed interface and theme customization.