PhotoBrush has a modern, easy to use multi-document interface.
Here is the typical screen of PhotoBrush. You see 2 opened images, a Brush Tool Bar with Expanded Retouch Bar on the left side and a Color & Texture Bar and Brushes Bar on the right side. The edit tools, like copy/paste, zoom or text are on the top toolbar.
However some tools will also show additional Bars and options.
See the description of the main toolbars.