https://www.denizcemonduygu.com/philo/browse/

History of Philosophy: Summarized & Visualized

This could be thought of as a form of digital, single-project zettelkasten dedicated to philosophy. It's got people, sources, and ideas which are cross linked in a Luhmann-sense (without numbering) though not in a topical index-sense. Interestingly it has not only a spatial interface and shows spatial relationships between people and ideas over time using a timeline, but it also indicates—using colored links—the ideas of disagreement/contrast/refutation and agreement/similarity/expansion.

What other (digital) tools of thought provide these sorts of visualization affordances?

machine translation (Google):

Other collections have never been used for their intended purpose. The Germanist Friedrich Kittler, for example, created index cards for all the colors that were ascribed to the moon in poetry. Someone could write the book about it with the help of these slips of paper.

Germanist Friedrich Kittler collected index cards with all the colors that were ascribed to the moon in poetry. He never did anything with his collection, but it has been suggested that one could write a book with his research collection.

machine translation (Google)

Quite a few boxes have been created for just one book, Siegfried Kracauer's collections for his monograph on Jacques Offenbach, for example, the photo archive of the historian Reinhart Koselleck with sections of thousands of photos of equestrian monuments, for example, or the box by the Romanist Hans Robert Jauß, in which he wrote for his Habilitation dissertation bogged down medieval animal names and characteristics.

A zettelkasten need not be a lifetime practice and historically many were created for supporting a specific project or ultimate work. Examples can be seen in the work of both Robert Green and his former assistant Ryan Holiday who kept separate collections for each of their books, as well as those displayed at the German Literature Archive in Marbach (2013) including Siegfried Kracauer (for a monograph on Jacques Offenbach), Reinhart Koselleck (equestrian related photos), Hans Robert Jauß (a dissertation on medieval animal names and characteristics).