Softimage|3D does not have scripting. It has expressions, and you can embed scripts into menus, but no scripting environment built in.
The scripting environments are in Softimage|XSI - the successor to Softimage|3D. XSI supports any ActiveX compliant language including: Jscript (JavaScript), VBscript (Visual Basic script), Perlscript (Perl), and PythonScript (Python). XML, HTML, and other markup languages are also supported so you can use webpages inside of the interface and make your own GUI's if you don't like XSI's scripting GUI architecture controls. The web stuff is available in the Net View.