Steffen Rörtgen builds metadata infrastructure for open education: linked data, SKOS vocabularies, and Nostr-based systems. Blog, work, and publications.https://steffen-roertgen.de/https://steffen-roertgen.de/articles/u-FPi10MVJ5GHRkGdis0X/https://steffen-roertgen.de/articles/u-FPi10MVJ5GHRkGdis0X/A year ago I wrote Just calling it Open is not enough, an essay about why public education infrastructure keeps reproducing the lock-in mechanisms of commercial platforms, and why the Nostr protocol could be a way out. The argument in a nutshell: The openness and collaboration we demand and desire could not previously be implemented technically without leading back to centralization.Mon, 24 Aug 2026 12:16:44 GMThttps://steffen-roertgen.de/articles/h-k72fOoZmf_SOC3cUpqc/https://steffen-roertgen.de/articles/h-k72fOoZmf_SOC3cUpqc/Wie kann Nostr helfen, den Herausforderungen öffentlicher Bildungsinfrastrukturen zu begegnen?Wed, 04 Jun 2025 08:08:27 GMThttps://steffen-roertgen.de/articles/h-k72fOoZmf_SOC3cUpqc-en/https://steffen-roertgen.de/articles/h-k72fOoZmf_SOC3cUpqc-en/How can Nostr help to tackle challenges in public and open education infrastructures?Wed, 04 Jun 2025 08:08:27 GMThttps://steffen-roertgen.de/articles/w6P1QgkZcK-lFNzaBGlbg/https://steffen-roertgen.de/articles/w6P1QgkZcK-lFNzaBGlbg/I want to propose a way on how to standardize metadata sent along with the tags attribute. For this I suggest the use of Linked Data technology to make it easy for developers and applications to use data from different…Sat, 15 Jul 2023 22:12:01 GMThttps://steffen-roertgen.de/posts/2023-03-18/https://steffen-roertgen.de/posts/2023-03-18/(scroll down for german-version)Sat, 18 Mar 2023 00:00:00 GMThttps://steffen-roertgen.de/posts/2023-03-11/https://steffen-roertgen.de/posts/2023-03-11/TL;DR: Meine Erfahrungen beim Aufsetzen eines NOSTR-Relays auf Basis von nostream und erste Interaktionen mit nostr-tools. Fazit: Super easy aufzusetzen und aufgrund des simplen Protokolls einfache Entwicklung von…Sat, 11 Mar 2023 00:00:00 GMThttps://steffen-roertgen.de/posts/2023-02-08/https://steffen-roertgen.de/posts/2023-02-08/(Ist noch work in progress)Wed, 08 Feb 2023 00:00:00 GMThttps://steffen-roertgen.de/posts/rdf-reasoning-over-linked-curricula/https://steffen-roertgen.de/posts/rdf-reasoning-over-linked-curricula/Scroll down for german versionWed, 12 Oct 2022 00:00:00 GMThttps://steffen-roertgen.de/posts/europass-vocabularies/https://steffen-roertgen.de/posts/europass-vocabularies/Long time no see!Thu, 16 Jun 2022 00:00:00 GMThttps://steffen-roertgen.de/posts/2021-08-01/https://steffen-roertgen.de/posts/2021-08-01/Vom 23.08. bis zum 25.08. fand das diesjährige Jointly-Sommercamp statt. Neben dem Austausch über aktuelle Entwicklungen, Ideen und Konzepten stand auch dieses Jahr wieder ein Hackathon auf der Agenda. Besonders im Fokus…Sun, 01 Aug 2021 00:00:00 GMThttps://steffen-roertgen.de/posts/reification/https://steffen-roertgen.de/posts/reification/This blog post is still a bit in progress, but I had to put it out here!Sat, 13 Mar 2021 00:00:00 GMThttps://steffen-roertgen.de/posts/linking-the-data/https://steffen-roertgen.de/posts/linking-the-data/Some time has passed since the last post and quite some things have happened. The wirlernenonline-project has published a data-dump of its index and I want to take this as a basis and show, what great things we will be…Thu, 03 Dec 2020 00:00:00 GMT