Download of ZDecimalJava 4.0 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. This free software for Mac OS X is a product of Benjamin White. We recommend checking the downloaded files with any free antivirus. ZDecimalJava for Mac lies within Education Tools, more precisely Science.
From the developer:
ZDecimalJava is a free and open source zone decimal conversion tool for your Mac. It is an application for IBM Z/Series packed and zone decimal conversion routines in Java. The program offers support for hexadecimal dump of records and field display.
You may want to check out more software for Mac, such as Genealogy Pro, sciatrope or Curvus Pro X, which might be similar to ZDecimalJava.