https://zettelkasten.de/authors/christian/<br /> https://www.reddit.com/user/divinedominion/ (evidence: https://www.reddit.com/r/c64/comments/1bg0ja1/does_anyone_have_the_zettelkasten_program_from/?utm_source=share&utm_medium=web2x&context=3, though there are certainly others)

Based on context here, u/WM2D2 of Florian Lengyel of zettelkasten.de context.

Interesting to see the first post on zettelkasten.de in 2013 has a photo of hawkexpress' Pile of Index Cards (PoIC) in it.

This obviously means that Christian Tietze had at least a passing familiarity with that system, though it differed structurally from Luhmann's version of zettelkasten.

This is the first post of what would become the https://zettelkasten.de site/blog dated 2013-06-20.

(This is the first archived version on Archive.org dated 2013-09-16)

https://forum.zettelkasten.de/profile/chrisaldrich

https://lifehacker.com/im-ryan-holiday-and-this-is-how-i-work-1485776137

An influential productivity article from 2013-12-18 that is seen quoted over the blogosphere for the following years that broadened the idea of the commonplace book and the later popularity of the zettelkasten.

Note that zettelkasten.de was just starting up at about this time period, though it follows the work of Manfred Kuehn's note taking blog.