The krz-files are 3D-5D cross stitch DESIGN files, like the can-files in Husqvarna/Pfaff software and the eof-files in Embird. They have to be converted to EMBROIDERY files before they can be used. So they are only useful if you have Husqvarna/Pfaff software. I think no other software could convert them.
Great question! Thank you for asking so the rest of us will find out too!
I see you have your answer. It is a design file for Cross Stitch. I have a version of Husqvarna in which I can open and save them. Shirley
I found it here: