Is there a program for OS X that can be used to create "fake" software box images?
I'm basically looking for something that will let me create this, but without Photoshop.
Box Shot 3D has a Windows and Max version. It renders high quality images, and does shadows, reflections, transparency, etc. You can even render books, business cards, and soda cans. Ironically, you can only order online so they likely don't ship you a box, but hey that's what this is all about, right? USD 60 at time of writing.
I just tried out the demo for fun and this is about as easy as it gets. Even if I was printing/shipping a product, I'd buy this just to mock up the box and spin it around on all axes to get an idea of how it will look on the shelf.
The real version does not have the watermarks (black horizontal lines).
You could create such Box-Shots with The Gimp (respectively the MacOS version of it). On the other hand it might also be possible using Blender for the rendering, and any paint program for the texture of the box.