PhotoQt is a simple, yet powerful and good looking image viewer, written in C++/Qt, published as open-source, and completely free. Developed by Lukas Spies
License: Open Source
ACDSee is a comprehensive photo editing and management tool suitable for professional photographers, offering advanced editing tools and file management features. In contrast, PhotoQt is a lightweight, open-source image viewer focused on simplicity and speed, making it ideal for casual users who need a fast way to view images without extensive editing capabilities.