Except Alpine & those based on it, which uses Linux but not GNU libc or GNU coreutils or GNU BASH… Just musl libc & Busybox. I.e. the entire subject of this thread is one of the non-GNU Linuxes.

Yes, I listed sysvinit for that reason. And Musl instead of glibc. GNU is optional in a Linux distro, except for the kernel’s use of a GNU license.

Sure, I should have gone further.

Systemd/GNU libc/GNU Coreutils/GNU BASH/Linux/X11//GTK/GNOME
Systemd/GNU libc/GNU Coreutils/GNU BASH/Linux/X11/GTK/LXDE
Systemd/GNU libc/GNU Coreutils/Zsh/Linux/X11/GTK/GNOME
Systemd/GNU libc/GNU Coreutils/Zsh/Linux/X11/GTK/LXDE
SysVInit/musl/Busybox/tcsh/Linux/csh
Systemd/GNU libc/GNU Coreutils/Zsh/Linux/Wayland/QT/KDE Plasma
Systemd/GNU libc/GNU Coreutils/Zsh/Linux/Wayland/QT/LXQT

etc, etc.

There are thousands of combinations of the possible layers needed to make an OS.

Systemd/GNU/Linux/GTK or Systemd/GNU/Linux/QT, really…

Swap files are useful if you are still on EXT4 or similar. If you’re using ZFS or BTRFS or BCacheFS, they have no benefits.