Cleaning up a Mac is something many users never do, but if you want to squeeze all the performance and disk space you can out of your Mac, you need a tool like Onyx.
A free multi-purpose utility, Onyx lets you run a myriad of system tasks such as disk maintenance, cache clean-up and index rebuilding. You can use Onyx to clear away the cobwebs that collect in things like the browser cache, font caches, boot, kernel and extension caches, as well as logs from crash reporters, system diagnostics and Software Update. If that wasn't enough, you can also get Onyx to delete previous iTunes libraries, the QuickTime Content Guide, recent items lists and even Mail downloads. OK, you can do most of these things yourself manually, but Onyx makes it fast and easy to do it all from one place.
Cleaning isn't the only talent Onyx has -- it's able to do quite a few maintenance and repair tasks such as verifying your startup disk, which it will do on it's first run automatically. By rebuilding the Spotlight Index or LaunchServices, you can often cure small corruption issues with your Mac. You can check the S.M.A.R.T. status of your internal disks, verify file structure and fix disk permissions without having to open Disk Utility. Onyx will also let you change some hidden preferences in Finder and other Apple programs such as iTunes and Mail, allowing you to tweak a few things here and there.
Onyx is a great free system utility that we've covered many times in the past and which allows you to perform a load of different tasks all from one application. If you're interested in cleaning out OS X, download Onyx today. By the way, Onyx also works well with OS X Lion.