Quibble: a custom, open source Windows bootloader

Quibble is the custom Windows bootloader - an open-source reimplementation of the files bootmgfw.efi and winload.efi, able to boot every version of Windows from XP to Windows 10 1909. Unlike the official bootloader, it is extensible, allowing you to boot from other filesystems than just NTFS.

This is only a proof of concept at this stage - don't use this for anything serious.

Quibble can boot Windows from Btrfs, which is impressive enough in its own right.