Operating system utilities for macOS
OnyX is the main application. The Maintenance, Deeper, and CalHash applications are parts of OnyX.
Thus, if you use OnyX, the Maintenance, the Deeper, and the CalHash applications are redundant!
All the applications are signed and notarized.
OnyX is a multifunction utility for macOS that you can use to verify the startup disk and the structure of its system files, to run tasks of cleaning and computer maintenance, to configure some hidden parameters of many Apple applications, and more.
Maintenance is an utility for macOS that you can use to perform miscellaneous tasks of maintenance and cleaning.
Deeper is a personalization utility for macOS that you can use to enable and disable the hidden functions.
CalHash is an utility for macOS that you can use to calculate and compare the checksum for a file.
Read the software license agreement carefully before using the applications.