Photo-Brush has a modern, easy to use multi-document and fully dockable interface.
Here is the typical screen of Photo-Brush. You see 2 opened images, a Brush Tool pane with Expanded Retouch tab docked on the bottom of the screen, a Color & Texture panes and Brushes pane docked on the right side and Actions pane with several pre-programmed actions on the left side. The edit tools, like copy/paste, zoom or text are on the top toolbar. However, some tools will also show additional panes and options.