MIT Media Lab and the MIT Center for Civic Media. FOLD is an open-source "reading, authoring, and publishing platform allowing storytellers to structure and contextualize stories." build stories using narrative cards and context cards. narrative cards are the blocks of text that tell the story; context cards are the videos, maps, photos, gifs, tweets, interactive visualizations (or just about any other media format) that accompany select words and phrases in each narrative card.