XnView MP stands for Multi Platform = it is available for Windows, Linux and MacOS. It is a continuation of the older XnView Classic. In my opinion it is a great alternative to Windows photos app or any Linux image viewer that comes preinstalled. I even think it is an alternative to IrfanView. It is really fast and simple to use, supports more than 500 image formats, has built in folder browser, image converter, editor... AND MORE!
Krusader - Krusader is an advanced twin panel (commander style) file manager for KDE and other desktops in the *nix world, similar to Midnight or Total Commander.Get your copy of the Krusader .
IrfanView - IrfanView ... one of the most popular viewers worldwide.
Midnight Commander - GNU Midnight Commander is a visual file manager, licensed under GNU General Public License and...
FastStone Image Viewer - FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor.
Vifm - Vifm is a ncurses based file manager with vi like keybindings.
JPEGView - JPEGView is a small and fast viewer/editor for JPEG, BMP, PNG, GIF and TIFF images.