There will no doubt be Terminal gurus out there horrified at the thought of getting under the bonnet of Mac OS X with anything other than the command line; for the rest of us there's TinkerTool. Now updated to version 4, this smart utility provides access to 'hidden' preferences, enabling you to fiddle with Finder, the Dock, Safari, appearance settings and more.

Despite this release being a complete rewrite, long-time users will find the interface familiar, and newcomers should find everything straightforward.

The toolbar enables you to choose what you want to amend. Select a category and you're presented with various clearly labelled and logically arranged menus and checkboxes for adjusting settings, such as Dock animations, and the screenshot save location.

In this latest release, Snow Leopard and QuickTime X are finally covered, including interface, concurrent recording and trimming options for OS X's built-in media player.

The app's user-friendly nature is evident throughout. Change settings for Finder and the Dock and you can restart either by clicking a button. Reverting to your Mac's pre-Tinker Tool settings or default state is a matter of clicking a button in the 'Reset' section.

To that end, it's hard to find fault with TinkerTool. It would be useful if the app's Help provided some insight into the more esoteric settings, but that's an extremely minor niggle.

Overall, TinkerTool is best in class – it's robust, usable, useful and free; tinkerers can't really ask for more.

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