Heroes of Horror was published by Wizards of the Coast for for Dungeons & Dragons 3/3.5 Ed.
Credits: Small portions of Chapters 1 and 2 (including the sample encounter "To Grandmother’s House"), the entirety of Chapter 3, the "Campaign Rules" section of Chapter 4, large portions of Chapter 5 (including the dread witch and purifier of the hallowed doctrine prestige classes), and a large portion of Chapter 6 (including the "Villains in Horror" section and roughly half the new monsters).
Notes: My first WotC gig, and a cooler concept than I could have asked for. 🙂
Tome of Magic was published by Wizards of the Coast for for Dungeons & Dragons 3/3.5 Ed.
Credits: Shadow Magic (except organizations and locations).