OnyX is a multifunction utility that you can use to verify the structure of the system files; run miscellaneous maintenance and cleaning tasks; configure parameters in the Finder, Dock, Safari, and some Apple applications; delete caches; remove certain problematic folders and files; rebuild various databases and indexes; and more.

OnyX is a reliable application which provides a clean interface to many tasks that would otherwise require complex commands to be typed using a command-line interface.