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
