CombineZ is free image-processing software package for creating images with extended depth of field.
The current release is CombineZP (CombineZ-Pyramid), successor to CombineZM (CombineZ-Movie) which was based on CombineZ5 (designed for older versions of Windows and is no longer maintained).
[1] CombineZ processes a stack of images (or frames) and is most frequently used to blend the focused areas of several partially focused digital photographs, usually close-ups, in order to create a composite image with an extended depth of field, created from the in-focus areas of each image.
It can take videos and split them into individual frames which are then manipulated for focus stacking.
Alternatively, it can convert a sequence of static frames into a movie (including generating intermediate transitional frames for smoothness) or a pseudo-3D 'rocker' image stack animation.