GVFS

GVFS is the virtual filesystem for the GNOME desktop, which allows mounting local and remote filesystems as a user along with trash support. It is also used by file managers like Thunar.

Installation

The gvfs package needs to be installed, along with polkit-gnome for the polkit rules.

Make sure the authentication agent provided by polkit-gnome is autostarted as described in Polkit#Authentication agents.

GVFS without root password

In file managers (e.g. Thunar), when you try to mount a drive, you might see that you need to enter the root password to continue every single time you want to mount and unmount a drive. This can be bypassed by setting a polkit rule.

In the directory /usr/share/polkit-1/rules.d, create this file named 10-drives.rules:

polkit.addRule(function(action, subject) {
if (action.id.indexOf("org.freedesktop.udisks2.") == 0){ 
       return polkit.Result.YES;
   }
}
);

Drives will now mount without any intervention from you. If you need to specify which users can perform this action or other restrictions, refer to polkit manual page.