As good an image editor GIMP is—out of the box, it can fall short of Photoshop at times. That said, you can use plugins to extend GIMP's functionality, and these make it even more powerful than ...
GIMP already has the bones of a serious editor, layers, masks, color management, and enough menus to make you squint. The tricky part is crossing that invisible line between "I can edit" and "I can ...