Download link:
https://www.digikam.org/download/
Older versions:
https://download.kde.org/Attic/digikam/
What is digiKam?
digiKam is an advanced open-source digital photo management application that runs on Linux, Windows, and MacOS. The application provides a comprehensive set of tools for importing, managing, editing, and sharing photos and raw files.
More information of capabilities at https://www.digikam.org/about/
Documentations and guide:
https://docs.kde.org/trunk5/en/digikam-doc/digikam/index.html