Joshua Ziff wrote:

Know-How Transfer's spatially-based contrast adjustment tools are unique, I think.

Shape and Wow! both work in the frequency decomposition domain indeed. Wow! (especially the pro version), could be thought as, if you will, a modern re-interpretation of the old Kai Power Tools Equalizer.

On one hand, it's quite easy to work with equalizer-like sliders, on the other hand the decomposition (e.g. Base + 5 Detail layers) is quite powerful for retouching and contrast boost as well. In addition, it works with either a Gaussian or Bilateral (aka Surface Blur) kernels, that have been re-implemented on a plugin level for accuracy and performance reasons.

Public disclosure: I've contributed to the products development, but my shares are so low that this shouldn't be seen as advertising or a personal plug :-)

Davide Barranca