OnyX is the main application. The Maintenance and Deeper applications are parts of OnyX. Maintenance is similar to the OnyX Automation pane, and Deeper is similar to the OnyX Parameters pane. OnyX is a multifunction utility that you can use to verify the startup disk and the structure of its 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.