stix is an InstallShield 3 extractor created by Veit Kannegieser. This version has been modified by me so that it works on Linux.
Please see the wiki page Building for the latest instructions.
To use stix, run:
stix FILENAME TARGETDIRECTORY
where FILENAME is the name of your data.z file and TARGETDIRECTORY is the root directory where it should be extracted.
It would be nice to be able to use stix as a backend to extract data.z files in graphical archiving tools.