From publisher blurb:
If the spell-slingers in your game are losing their magic for you, this book may be what you need! Inside, you will find the rules for playing a new arcane class, the mage, that casts arcane spells in a whole new way. Like many magical characters from fiction, the mage isn't limited by a list of prepared spells for the day, or by a limited number of spells he can cast before resting. Instead, he prepares the spells as he needs them, at will. Also included are rules for specializing the mage to your style, and suggestions for how to play this new class.
This product is compatible with the Pathfinder Roleplaying Game, and is 100% open gaming content.