allmemory, fs_usage, fuser, latency, sar, sc_usage, spindump: Display various system usage statistics.
bless, disklabel, disktool, diskutil, drutil, fsck, hdiutil, pdisk: Create, identify, manage, and fix Mac OS X disks, file systems, and disk images.
ioreg, kextstat: Show device drivers and other kernel extensions in use.
mDNS, dns-sd: Test Bonjour service discovery with these diagnostic tools.
open: Invoke launch services on an arbitrary document or application as if doubleclicking it in the Finder.
pbcopy, pbpaste: Move data between stdin/stdout and the Mac OS X pasteboard.
say: Convert text to audio output or a file via Speech Synthesizer.
shasum: Compute or validate SHA message digests.
sips: Manipulate the format and color space of bitmap images (for example, rotate,
sw_vers, uname: Display Mac OS X version information.
syslog and logger: Send, view, and manage system log messages with these modern
xattr: List, display, set, and delete file system extended attributes
You can find more information on apple.com in this documentation.