Double Commander is a cross platform open source file manager with two panels side by side.
Icon

doublecmd
Package
app-install-data
Ubuntu applications (data files)
doublecmd-qt
twin-panel (commander-style) file manager (Qt4)
doublecmd-common
twin-panel (commander-style) file manager
doublecmd-gtk2
twin-panel (commander-style) file manager (GTK2)
doublecmd-qt4
twin-panel (commander-style) file manager (Qt4)
doublecmd-qt5
twin-panel (commander-style) file manager (Qt5)
doublecmd-gtk
twin-panel (commander-style) file manager (GTK2)
Reads mimetypes
inode/directory
folder