As you may already know, Darktable is a free and open-source photography workflow application for image editing (that be used hand-in-hand with GIMP) with good support for Linux, Mac OSX, Solaris and Windows. It’s main purpose is to enhance a photographer’s workflow, permitting you to manage and adjust a large number of images efficient and easy.
Darktable operates in two modes: Lighttable (which allows you to export, sort and rename images) and Darkroom (which permits editing photos and raw files). The GUI looks very similar to Lightroom Classic, so if you have used that already, you might feel at home.