This website contains operating system utilities for macOS. You may download, copy, use them for as long as you want to do so, and distribute them at no charge.

OnyX
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.

Maintenance
Maintenance is an operating system maintenance and cleaning utility for macOS that you can use to perform miscellaneous tasks of computer maintenance: run periodic scripts; rebuild the databases; delete application, font, and system caches; and more.

Deeper
Deeper is a personalization utility for macOS that you can use to enable and disable the hidden functions of the Finder, Dock, Safari, iTunes/Music, login window, and many Apple applications, and more.