Microsoft just released a new Windows 10 Insider Preview build featuring the Windows Subsystem for Linux 2. WSL 2 includes a real Linux kernel that lets you run more Linux software on Windows and with better performance than WSL 1.
This new version of WSL 2 uses Hyper-V features to create a lightweight virtual machine with a minimal Linux kernel. It will still be available on Windows 10 Home, however, even though Hyper-V isn’t normally available on Windows 10 Home. Expect better compatibility with Linux software, including support for Docker, and “dramatic file system performance increases.”
The virtual machine will automatically launch at startup and use a bit of memory in the background, but Microsoft promises it “has a small memory footprint.” You can run the wsl --shutdown command if you ever want to shut down the background VM.
WSL 2 is part of the development builds for Windows 10 20H1, which is expected for release around April 2020. WSL may be part of Windows 10 19H2, expected for release around October 2019, but Microsoft isn’t testing 19H2 yet.
The latest Windows 10 Insider build includes some other useful features, too. You can now head to Settings > Update & Security > Delivery Optimization > Advanced Options to throttle Windows Update. For example, you can set Windows Update to only use 1 Mbps or a specific percentage of your available bandwidth while downloading updates in the background.