How we made the Gutenberg Sci-Fi Shelf

Nothing was placed by hand. We took Project Gutenberg's own catalogue of its Science Fiction shelf and let the books' own subject headings become the structure — motifs like time travel, Mars, robots, and alien life standing as branches, each thick with the stories that share it. Every leaf is a single book, linking out to read it in full at Project Gutenberg. The coral simply renders the shape the collection already had.