On Windows, the sishell.bat file is used to start up an MS-DOS command prompt window with SOFTIMAGE|3D environment variables already loaded so that you can run SOFTIMAGE|3D standalones (soft -r, Viewer, dbtools, imgconv, etc.).
Sample sishell.bat file
@echo off
title "Softimage(R) 3D v4.0 MS-DOS Command Prompt"
cmd /K call d:\Softimage\SOFT3D_4.0\3D\bin\SETENV.BAT
echo on