It's no secret that I'm desperately in love with the FATE system; I think it's elegant as hell, and use it for everything under the sun. How? That's where the Toolkit comes in.
With this book, you're looking at just shy of 200 pages worth of optional rules and game advice. Want to shake up the default skill list, or change the expected power level of the player characters? That's in here. Want a magic system in FATE? You'll get five different ones, plus cybernetics, superpowers, and advice for building your own subsystems. Need help turning FATE into a horror game? That's in the book, too. Class systems, squad combat, kung fu, social combat, swashbuckling, vehicles, mass warfare, help for setting design and character creation... if you can think of a topic, this book deals with it in an informative and easy-to-grasp manner.
The layout is clean, the art's functional (not great, not bad, but often unique; for every dwarf or wizard, there's a cybernetic gorilla or a six-armed alien swordsman), and the meat of the book is stellar. If you're playing FATE, you'll find something worth using between the covers. It comes with my highest praise.
[5 of 5 Stars!]