The CLIX package includes a starter database file with over 1,100 system commands for investigating your system status, for cleaning out junk files, for getting at esoteric secret settings in your most used applications - and more.
And most importantly, CLIX is infinitely extensible: you can add to it at any time, in any way you please - add new commands, new command categories, new command database files, and so on.
And unlike other systems, CLIX is 100% 'WYSISYG' (what you see is what you get): it's exactly the command lines you would use at a terminal if you were so inclined. So sometime you might remember a command or two and try it on your own.
CLIX comes with commands for viewing all your system logs, for cleaning out browser caches, for pruning and fixing 'plist' preference files, for spelunking in root's back yard, for ridding your system of all kinds of junk, for seeing what your virtual memory is up to, what your Netinfo database manager is up to, and on and on.
CLIX also has its own newsletter and command exchange for in-depth discussion of Unix and the CLIX commands.
Maintain your Mac safely and securely.