Python modulesfor use in writing Python programs With Statistics 22 or later, you can see summary information and download and install extensions from within the product using Utilities > Extension Bundles > Download and Install Extension Bundles. For a pdf document with a summary view of the IBM-written extensions, go here. These all require one or more plug-in or Essentials. Extension Commands – add-ons for IBM SPSS Statistics that work like standard syntax.