New home for the [in]famous filesystem BTRFS

RedHat discontinued BTRFS for a number of reasons.

BTRFS will be default FS in ReactOS

Because it is better than FAT and has feature complete driver for Windows

It has a ZFS feature set, but was designed with non-server workloads in mind.

What is the best modern filesystem in your opinion ? (supported on linux)

I'm not sure if you mean "user" or "reactOS devs".

If the latter, I can't be sure (besides the fact it's modern and has plenty of features), but as a user, I chose btrfs for its "subvolumes".

With subvolumes, you can selectively mount subdirectories in the partition without an explicit "bind" mount.

For example, I have 3 linux installs on subvolumes /rootfsUbuntu1804 /rootfsArch /rootfsFedora27. They all share the whole partition so I wont regret giving one too much space that it will never use, or worry about resizing partitions to create a new one. The fstab of any looks something like:

    UUID=...  /  btrfs subvol=rootfsUbuntu1804,compress 0 0 

(the "compress" option there is also neat.) If using as /, you must add rootflags=subvol=rootfsUbuntu1804 to your boot options.

I also have my home directory and other "shared filesystem" things (like docker) as subvolumes, each being shared to reduce redundancy. The only downside is graphical file managers see each mount as a "device" so I have a lot of noise in the sidebar of Dolphin or Nautilus.