There’s a reason Onyx has been among the tools of choice for Mac techies for almost two decades now, the final program you ran on a client’s computer to clean things up before you wrapped things up. Other great apps like macOS are elementary OS (Free, Open Source), Linux Mint (Free, Open Source), Debian (Free, Open Source) and Manjaro Linux (Free, Open Source). It’s to Joël Barrière’s credit that the program is able to dive into system components as well as it does, and Barrière’s does his homework and listens to user feedback to create an excellent freeware program while only asking for donations in return if the customer is satisfied with the product. The best alternative is Ubuntu, which is both free and Open Source. It’s been a long time since the heady days of 2003. There are some handy FAQ links on the Titanium Software website as to common issues Onyx works to address. Since the days of Mac OS X 10.2 Jaguar, Onyx has been in the arsenal of Mac techies to help fix Macs and assorted operating system weirdness. Onyx has never tried to be a jack of all trades like some of the other Mac utilities, nor does it go out of its way to welcome the user with a tutorial video. The Restore Defaults option under the Maintenance tab also comes in handy and provides an easy escape if you’ve changed a system setting and things appear to have gotten out of hand.
Onyx is the kind of program you research before using and given its potential reach into your operating system’s components, it behooves you to read up on it or look into some YouTube tutorial videos to get familiar with how to operate Onyx, which items to repair via clicking checkboxes in the menus, which items to avoid, and how to safely use the program. The customizable Maintenance tasks screen in Onyx.