Any more "hidden" yet useful "apps/utilities" in Mac OSX?

[atlanticza]

Macs have the Unix utility, CUPS (Common Unix Printing Service) to manage/install your printers. Just cut and past the numbers 127.0.0.1:631 into your browser to access it.

Very handy and I was wondering how many other "hidden" but very useful apps/utilities are built into in Leopard - apart from the obvious ones, of course.

 

[pjrobertson]

Everything UNIX has. There's so much hidden in the terminal

 

[SHankara]

there a whole bunch of the unix gnu stuff you can compile yourself,X11 and open source guis usually pose problems GTK QT KDE GNOME etc.

you can use the tool "file" then the path to the certian jpg mpg to figure out what type of file it is without going through the slow get info window