This document discusses the history of fan engagement and interactivity. It identifies five patterns of fan engagement: identification, mastery, production, participation, and appropriation. It explores the evolution of fandom from virtual communities to participatory culture and the role of fans as early adapters, influencers, and experts. It also examines commercial fan productions in genres like hip-hop, doujinshi, fan films, game mods, and literary appropriations as well as debates around whether fan productions should be free or commercialized. The presenters are Ivan Askwith, Henry Jenkins, and Abigail De Kosnik discussing the topic at SXSW Interactive in 2009.