From the Introduction to The Witch's Brew:
The Advanced Feats series takes the idea of a feats supplement to a new level. Instead of providing a dry list of feats, Advanced Feats helps you put them into context to build interesting and powerful characters. For the advanced player, we hope to spark your imagination. For the casual player, we hope to show you the path to making fun characters. For the GM, Advanced Feats provides feats that your players can use without slowing down or unbalancing your adventures.
Advanced Feats draws heavily upon the Netbook of Feats, an Open Gaming License (OGL) publication for feats in the d20 system.
Each feat in this book has been either carefully re-worked to be fully compatible with the Pathfinder Roleplaying Game or created specifically for this book based on the new Advanced Player's Guide classes.