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. It’s been a long time since the heady days of 2003, and along the way, French developer Joël Barrièrehas has continuously released steady updates of the popular free customization and maintenance tool.
With Onyx at hand, permissions can be repaired, databases rebuilt, file structures reorganized, hard disk structures checked, and indexes restored. The program is excellent at digging into deeply-rooted chunks of macOS, setting and repairing Unix-level functions that would otherwise only be accessed through the Mac’s Terminal program and the command line, and rooting through odd settings to restore functionality after you’ve slogged through strange errors and weird behaviors from your Mac.
Onyx also combines a unique, bare-bones approach to its user interface while offering an incredible level of customization as to what files are affected during a repair.