IrfanView - IrfanView ... one of the most popular viewers worldwide.
digiKam - Professional Photo Management with the Power of Open Source
ImageGlass - You can use Image to view your digital images and photos of many different formats.
ACDSee Photo Studio - ACDSee becomes ACDSee Photo Studio — ACDSee Photo Studio Standard 2018 continues the ACDSee legacy
XnView MP - XnView is a free software that allows you to view, resize and edit your images. It supports more than 500 different formats!
Shotwell - Shotwell is an open source photo organizer designed for the GNOME desktop environment.