There is the full version and the "Classic" (=Light version)
The light version is the same as the full version (same libraries, MUI-Classes, Virus checker, packer) but many of the applications removed (less than half of the size of the full version). All versions include Wanderer, Scalos and Magellan. On the download-page are instructions and tips to add f.e. Arexx or change to Scalos.
there are basically 3 options: Use Wanderer and Zune (preconfig) Use Scalos and Zune replacing Wanderer (different startup-sequence) Use Scalos and MUI replacing Zune and Wanderer (instructions on download-page)
Details on "Download-Page"
I would also recommend to replace Input, Locale and PSI by original files from 3.1. because there seems to be a bugs in these programs