Ranger is a text based file manager that works inside of a terminal emulator.
The default file manager for XFCE.
Dolphin file manager is the default file manager for KDE.
Midnight Commander is a cross platform file manager and a clone of Norton Commander.
PCManFM is the default file manager for the LXDE desktop.
Nautilus is the default file manger for Gnome Shell that is currently going by the name of Gnome Files.
Pantheon Files is the default file manager for elementary OS.
The MATE desktop fork of Nautilus.
ncurses file manager
SpaceFM is a fork of PCManFM that was created to be more customizable than PCManFM.
Multi-platform open source file manager.
Worker is a two-pane file manager for the X Window System on UN*X.