Feh (image viewer)
feh is a lightweight image viewer aimed mainly at users of command line interfaces.
Unlike most graphical image viewers, feh does not have any graphical control elements which enables it to also be used to display background images on systems running the X window system. feh offers six different operational modes which can be controlled via command-line flags; apart from the default slideshow there is thumbnail, index, montage, list, and multiwindow.