From publisher blurb:
They are the favorite foes of many a party of adventurers. In these pages, the drow come to life, their culture and powers detailed fully for the first time. This guide presents new rules galore; new spells, new magical items, insight into the mysteries of Lolth, Monstrous Compendium entries for related monsters of the Underdark-and much, much more.
Learn all about the drow herein, from the words of the ancient elven sage Erlathan Greycloak ("Proud, graceful evil. Cruelty personified; talent wasted, beauty lost in darkness" ) to the lore of the great sage Elminster ("Did I ever tell thee how close I came to having a drow wife? No? Well, then").