edit by Led:  Here is a video about how to install them
https://youtu.be/NvDMErhwm9Y

and here is the download (large) that includes softimage, ZETools, and software needed to run ZETools.
http://www.swbfgamers.com/index.php?action=downloads;sa=view;down=1371


XSI ZETools is a plugin(biggest part written in python) for XSI 6.0+.
It should do pretty much everything the Pandemic exporter could.

I update the gametoast topic with every new release, so that's the best place to get the newest download/info/support:
Gametoast topic
Here's the 'homepage':
http://schlechtwetterfront.github.io/xsizetools/
The latest version is maintained at github:
https://github.com/Schlechtwetterfront/xsizetools/