http://blog.kasson.com/the-last-word/do-sharper-lenses-have-more-or-less-dof/
The article are interesting, and I would like to add some historical context. Around the beginning of the 20th century, opticians produced lenses to increase depth of field (which was a problem with slow emulsions in large format view cameras). One of the most famous makers were Pinkham & Smith, but there were others.
These lenses were all soft focus lenses, which made sense as limited depth of field were a problem mainly for portraits. They achieved both soft focus and increased depth of field by adding aberrations, for example spherical aberration. Pinkham & Smith hand retouched the lenses to give the same effect. Others used chromatic aberration to the same effect (on B&W film, of course).
The idea is that a lens with spherical aberration or a hand retouched lens will have different focus distances according to the path the rays take in the lens. So the image looks like a composite of several images taken with slightly varied focus. We could do the same on static subjects by varying the focus a bit while taking multiple exposures on the same piece of film. This makes highlights look as if they glow with light but also increases apparent depth of field.
In the 70s some add-on filters were developed to the same effect. Basically, they had little low-power lenses on their surfaces. Some, I think from Minolta, made the power of these extra lenses depend on wavelength so that the effect would only appear on some colors, while preserving apparent sharpness on others. This way skin detail could be preserved with softening and increased depth of field on different colors.
These effects are impossible to emulate in post, unless using a light field camera. That is: the softening can be emulated, but the increased depth of field cannot, unless combining pictures taken with varied focus (which a light field camera does by principle). But I am not aware of software doing that.