Class Viewer allowed me to put out my minimalist design philosophy. From the outset I wanted to stay away from feature-creep and lots of buttons or menus or all those other things that developers are notorious for tossing into projects. So much so that even as a tech-savvy person I'm amazed still when I can't use my cellphone well, without consulting a manual, which tends to be incomprehensible. I joke you need a college course to properly use one of these things. (Of course modern kids seem to just inhale them, but they're genetic mutants who have evolved to use modern technology.)
So Class Viewer is designed to be a user friendly as possible--for real, not just saying it is.
Actually I wanted to toss menus entirely but found I couldn't, but I could deliberately break the traditional set of menus across the top!!!
The two window groups design was deliberate as well. My idea was of a larger dataset to your left, which you refine to a simpler set of data to your right. The program is focused around methods, so they can fill the left window, with results in the stacked windows on the right.
Of course I also wasn't excited about trying to put out a lot of languages for what I'd hope would be a useful app--there are too many around the planet and I just really know English--so I like to think that if you're shown how to use Class Viewer, you can use it in any language, and in fact downloads now come from roughly 30+ countries per seven days, according to SourceForge statistics, so maybe I achieved that goal.
So the simple answer to the design philosophy of Class Viewer is, simplicity.