OnyX OnyX is a multifunction utility that you can use to verify the structure of the system files, to run miscellaneous maintenance and cleaning tasks, to configure parameters in the Finder, Dock, Safari, and some of Apple's applications, to delete caches, to remove certain problematic folders and files, to rebuild various databases and indexes, and more. WARNING: There is a specific version of OnyX for each major version of the operating system.
Use the specific version, and don't try to use a non-compatible version.
Nov 11, 2007 Actually I wouldn't go as far as to say Onyx is safe to use. It is not a maintenance utility despite others calling it, Cocktail, Macaroni, Applejack, Jaguar-Tiger Cache Cleaners, and other multifunction utilities that do more than one task. The only safe utility to use is a backup utility.