In an article dated July 2006, designer Mike Mearls used the word 'homebrew' in a broader sense to refer to monster design. The usage of the term 'homebrew' evolved from fan-made worlds to fan-made game material in general. Wizards of the Coast also used the term in the context of campaign worlds in articles on the official Dungeons & Dragons website in 2005. In August 2003, the Wizards Community Boards had a forum named Homebrew for the purpose of home-made campaign worlds, suggesting that at that time the community used this word specifically to refer to campaign settings. The term 'homebrew' has been used by the D&D fan community at least as far back as 2003, where it was used to refer to to a home-made D&D campaign setting in contrast to an official published world: 'As someone who has not until recently learned much about Dragonlance, I'm excited to see what it can offer my homebrew campaign.' - kexizzoc87, 2003 The term entered metaphorical use for anyone who produces hobbyist versions of products which are normally produced only commercially, such as video games for consoles.
The word 'homebrew' originally referred to private individuals who brewed their own home-made beer or other alcoholic drinks as a hobby.