7.2 How can I tell what products have been loaded on my system?

For 9.x, Check the /etc/filesets directory. There is a file there for each fileset 
that has been loaded that summarizes the files in that fileset.  This directory is
used by the /etc/update, /etc/updist, /etc/netdistd, and /etc/rmfn utilities
for loading and unloading software.

For 10.x, use the swlist command.