cpdftk command line tools

GUI for the Unix find command-line tool.

Convert video files into the Handbrake Command Line Interface.

HoudahGPS is a front end to the open source command line tool GPSBabel.

GUI for the command line look tool.

rawr! is based on rarlab's os x command line utility

Images can be resized with the use of the command-line tool sizimg.

Gnuplot is a portable command-line driven interactive data and function utility.