6
When you go to
https://xoops.org/modules/core/ and choose to download XOOPS it does take you to sourceforge.
Under files, I still don't find the zip or tar archives for the XOOPS versions... I looked through the list of directories listed and also did an edit find from the browser for XOOPS 2.3.3 and it did not find it either...
My 2cents as a relatively recent user, is that this is rather confusing. I prefer the link Mamba posted above.