Double Commander is a cross-platform open source file manager with two panels side by side. It is inspired by Total Commander and features some new ideas.
Double Commander vs Far Manager opinions
Dual pane, full featured file manager.
GNU Midnight Commander is a visual file manager, licensed under GNU General Public License and therefore qualifies as Free Software. Its a feature rich full-screen text mode application that allows you to copy, move and delete files and whole directory trees, search for files...
Midnight Commander vs Far Manager opinions
GNOME Files, formerly known as Nautilus, is the official file manager for the GNOME desktop, giving the user a simple way to navigate and manage its files.
Thunar is a new modern file manager for the Xfce Desktop Environment. Thunar has been designed from the ground up to be fast and easy-to-use. Its user interface is clean and intuitive, and does not include any confusing or useless options.
SpaceFM is a multi-panel tabbed file and desktop manager for Linux with built-in VFS, udev- or HAL-based device manager, customisable menu system, and bash integration. SpaceFM aims to provide a stable, capable file manager with significant customisation capabilities.
muCommander is a lightweight, cross-platform file manager with a dual-pane interface. It runs on any operating system with Java support (Mac OS X, Windows, Linux, *BSD, Solaris...).
Advanced twin panel (commander style) file manager for KDE and other desktops in the *nix world, similar to Midnight or Total Commander. It provides all the file management features you could possibly want: extensive archive handling, mounted filesystem support, FTP, advanced...
JumpFm is a minimalistic dual panel file manager (currently released only for Windows, Mac, and Linux) that lets you navigate your file system very efficiently.Discontinued
The last release was in 2017, but you can still download it and use it.