It wasn't intended to be used this way, but Topaz Vivacity, developed for noise removal, interpolation, JPEG repair and sharpening, can create some nice color-etch type landscape effects when the sharpening settings are pushed near the top end.

Of course the effect can be used with any subject, especially those with contrast. Trees and leaves are especially nice. An added benefit is that Vivacity works well with soft or other slightly-off images that would otherwise be rejected.

The main news today is that a Mac version was just released, a few years after the Windows version came out.

Wow. Pretty interesting effect, and not at all what I was expecting to see.
Oddly, though, when I visited the website for it and clicked on the Buy button, the page that came up said that it was for Windows only. On the previous page, it says that it works on Mac or Windows. I guess they haven't updated the purchasing info?
-Ron H.

I've got the Mac Buy link activated now ;-).