Zerene Stacker for Focus Stacking
For the recent focus stacking example with the Pentax K1 and the focus stacking example with the Zeiss 135mm f/2 APO-Sonnar, I used Zerene Stacker (available for Mac and PC).
ZereneStacker is impressively fast and straightforward to use. This was the first time I had ever used it for these examples, and yet I had each stack done in under 5 minutes, a testament to simple but thoughtful design. No touchup was needed for the examples noted above.