The following FSD are shared with: https://github.com/maharmstone/btrfs.
-reactos/drivers/filesystems/btrfs # Synced to 0.7
+reactos/drivers/filesystems/btrfs # Synced to 0.8
reactos/dll/shellext/shellbtrfs # Synced to 0.7
+reactos/sdk/lib/fslib/btrfslib # Synced to 0.8
The following FSD are shared with: http://www.ext2fsd.com/