The file manager of the Lumina desktop environment.
Ranked in these QuestionsQuestion Ranking
Pro BSD 3-Clause
Its written under a real open license without copyleft.
Pro Based on Qt
As Qt is a real multi-platform toolkit that is not developed for one desktop and platform.
Pro Full ZFS support
It has full ZFS support including snapshots.
Pro No toolkits
It does not use freedesktop toolkits like polkit or dbus. It also does not use toolkits from other desktops like GNOME(GTK, ATK, GLIB, GIO etc.) or KDE(KF5/KIO).