“Premature optimization is the root of all evil in programming.”

Donald Knuth

Mengenlehreuhr – the Berlin Clock in SVG

A pure HTML/SVG/JS implementation of the Berlin Set Theory Clock, with neon glow effects and PWA support.

March 13, 2026


CipherPost – end-to-end encrypted messaging

A zero-knowledge messaging PWA built with Elm and Erlang — all encryption happens in the browser.

March 11, 2026


Stromfinder – interactive map of German charging stations

An interactive map visualizing ~70,000 charging stations in Germany using Elm and Leaflet.

March 9, 2026


Eliza.elm – an ELIZA chatbot in Elm

An ELIZA-inspired chatbot running serverless in the browser, written in Elm.

March 7, 2026


Ladesäulen – German charging station register as JSON

A tool that converts the official German charging station register into usable JSON.

March 30, 2024


TileCache for OSM tiles

A caching server for OpenStreetMap tiles, reducing traffic and saving resources on the real tile server.

March 23, 2024


Matcher – a simple expression matcher for Erlang

A tuple-based expression evaluator for comparisons, boolean logic, and substring matching in Erlang.

March 11, 2024


Playlist – an M3U parser in Erlang

An Erlang library for parsing extended M3U playlist files.

March 1, 2024


AhoyDTU HowTo for ESP8266

Wiring and more, to get AhoyDTU running on an ESP8266

February 17, 2024


Base45 2.0

base45 is available at hex.pm in Version 2

June 15, 2023


PLZ Suche – finding nearby zip codes

An Erlang application for finding zip codes geographically close to a given location.

February 2, 2022


Base45 – encoding for QR codes in pure Erlang

First release of my Base45 encoder for Erlang, the encoding behind EU COVID certificates.

July 20, 2021


Bencoding 1.0

Version 1.0 of my bencoding library in pure Erlang is now on hex.pm

December 1, 2019


Bencoding 0.2

Version 0.2 of my bencoding library in pure Erlang is now on hex.pm

April 2, 2019


Bencoding – BitTorrent’s data format in Erlang

First release of a Bencoding encoder/decoder in pure Erlang.

October 23, 2018


WordClock – telling time in words

A WordClock implemented in JavaScript, just for fun.

October 6, 2017


OpenGeoDB – a mirror of German-speaking geographical data

A git mirror of the OpenGeoDB data, available as CSV and JSON via GitHub Pages.

February 6, 2017


Netzfrequenz – measuring mains frequency with an Arduino

An Arduino sketch for determining the current mains frequency using nothing more than a piece of wire.

February 8, 2015


LernQuiz – a geography quiz in Elm

A multiple-choice quiz app about German federal states, European capitals, and national flags.

November 23, 2014