digiKam - Professional Photo Management with the Power of Open Source
XnView MP - XnView is a free software that allows you to view, resize and edit your images. It supports more than 500 different formats!
Photos on macOS - Photos keeps your images organized and accessible. Rediscover favorite shots with Memories. Access them on your devices with iCloud Photos.
Capture One - Capture One is an all-in-one photo-editing software that comes with all powerful tools to make your photo editing smoother and more precise than ever.
IrfanView - IrfanView ... one of the most popular viewers worldwide.
ACDSee Photo Studio - ACDSee becomes ACDSee Photo Studio — ACDSee Photo Studio Standard 2018 continues the ACDSee legacy