gThumb is an image viewer and organizer with a couple of limited options to also edit images.

Nomacs is a free, open source image viewer, which supports multiple platforms.

Adobe Bridge is a digital asset management app.

Corel PhotoImpact combines easy-to-use photo editing tools with inspiring photo projects and digital art to make digital photography and image creativity.

F-Spot is an unmaintained image organizer, designed to provide personal photo management for the GNOME desktop environment.

Xee is an streamlined and convenient image viewer and browser.

Viu 2 is a free image viewing/browsing software.