OnyX is a multifunction utility that you can use to run miscellaneous system maintenance and cleaning tasks, to configure hidden parameters in the Finder, Dock, and some Apple applications, to delete caches, to remove certain problematic folders and files, to rebuild various databases and indexes, to display UNIX manual pages, 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.