Onyx is a great tool that I have used for many years – it does many things. One of these is System Maintenance. Performing this from time to time can help keep your Mac running smoothly. It is also great if your are having trouble with some of your computer function running slow or you experience system crashes or freezes. It also fixes other problems with your web browsing, Apple Mail, Spotlight searches, Font problems, and several others. It is a very handy utility which I truly value.