Great book that really expands on the lore and the mechanical support for a dozen interesting races-- if you're a player who wants to try something different, or a worldbuilder sick of the Tolkien Trio, at least one of the races in this book is going to appeal to you.

Rock-solid attempt at making the 3.X/PF multiclassing system more functional. I've been trying to do the same thing for fifteen years and Overhauling Multiclassing is closer than I've ever come myself.

These rules now permanently form the basis for my own d20 houserules and homebrew design. Cannot recommend highly enough.