Question about Programs on LNX-BBC 2.1

I've seen on the BBC-LNX main web page under the RESOURCES | Package List
link the various categories like X11/and utils/ , and within these packages
like blackbox and tct and gcc .  However I've been able to find them .  I've
looked thru most of the directories and done   find / -name <filename>   and
received no hits.  What have I missed?.  I did see a reference to something
called 'downloadable packages' , what is this?