Looking for the missing modules

Documentation I have looked at is great!!!!

I am confused on one thing.  Where are the missing modules?  For
examlple, in the getting started guide, it mentions a calendar module
that is available in the modules distribution.  When I went to
sourceforge (via the download menu item) and downloaded the full
installation, the module was not included.   Where is it?

I search the Xaraya website and I find the a reference to calendar
module, but no place to download it.  Ironically, I see another person
asking my same question, where can they download the module?  So I guess
I'm not the only one who is confused on how to find these missing
modules.

I have also notice the same problem with