Most of the time OS X runs well without much intervention. However there are times when you want to do some cleaning, run automated maintenance at unusual times, or change settings that aren’t readily accessible from the user interface. Since OS X is based on a form of Unix, all of these things can be accomplished at the command line. However for most people, the command line isn’t very friendly. Not only is it hard to find the right command, but it can be very easy to make mistakes. OnyX solves many of these issues by giving you a clean interface to many of OS X’s internals.
The main toolbar of OnyX organizes it’s features into several categories. Appearance, Maintenance, Cleaning, Automation, Log Files and Unix Utilities.
The Appearance category gives you access to many hidden parameters in OSX that change the way things look. You can set it to show hidden files and folders, display or hide the eject button, change the way arrows show up in the scroll bar, and much more. Of particular note is the ability to keep OS X from creating .DS_Store files when using network drives. (If you regularly connect to Windows share’s you’ll appreciate this feature.) You can also enable/disable Expose and Dashboard and decide what type of users show up in the login list.
The Maintenance section of the program gives you access to the scripts that OS X runs go keep itself working smoothly. Apple has created Daily, Weekly, and Monthly scripts that help keep things cleaned up and optimized on your computer. However, if your computer is off when these scripts are scheduled they won’t run. Depending on your schedule the scripts could run very infrequently. You can manually run the scripts from this section of OnyX as well as reset the Spotlight index, Help files, links between documents and apps and verify/repair permissions. There is also an option to partially or completely optimize the entire system.
As you would expect, the cleaning section lets you clear out various caches and temporary folders on the system. The automation section gives you access to the cleaning and maintenance sections of the program in a way that is easy to run if you need to do it frequently. The log files give you a good view of the various logging information on your system, without needing to dig through a bunch of unix files manually. The unix utilities gives you a GUI wrapper of some of the things you can do from the command line. It also shows you all the unix commands on the system with their help files.
That covers most of the major parts of OnyX, but since the software is free (donations are appreciated), I encourage you to check it out here.