HDDerase
HDDerase is a freeware utility that securely erases data on hard drives using the Secure Erase unit command built into the firmware of Parallel ATA and Serial ATA drives manufactured after 2001. HDDerase was developed by the Center for Magnetic Recording Research at the University of California, San Diego. HDDerase is designed for command-line use only.
It differs from other file deletion programs such as Darik's Boot and Nuke which attempt to erase data using block writes which cannot access certain portions of the hard drive. The internal firmware Secure Erase command can access data that is no longer accessible through software, such as bad blocks.
Despite Secure Erase being known as the most effective method of data sanitization and despite it being trumpeted as such by multiple websites on the internet, due to the age of the software, few modern computers can communicate between the software and the hard drive, making it virtually unusable. In that sense, it's a carrot on a stick.