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Open Source is at the very core of We have designed the project from the ground up to be as open as possible. Our constitution requires us to publish our content under free licenses. We are huge proponents of Open Source and believe in it.

We sometimes posts updates on what we’re doing and interesting technical challenges we encountered in devlog and on Mastodon.

Our Open Source repositories


Here is an overview of important repositories that we have created—directly or indirectly—for They are of course published under free licenses. We invite you to take a look behind the curtain, contribute or use our work for your own projects! We warmly welcome issues and pull requests through the repositories.



MIT License

The website you are currently on. This repository not only contains the content but also the code for the generator, the privacy controls and more.
The site is designed to be primarily static and runs on Hugo and Preact.

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The data behind the project. This includes our company and supervisory authority databases but also the sample letters.
The repository is structured as a collection of plain text files that are both human- and machine-readable.

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MIT License

Our website used for hosting videos, This repository includes the source code and scripts used for the site.

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MIT License

A tool that allows you to generate letters (plain text or PDF formats) from pre-defined layout templates. This repository includes these layout templates and the scripts needed to render letters from them.

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We also want to run the non-profit behind this project, e. V., as openly and transparently as possible. Thus, this repository contains important documents with their change histories.

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MIT License

The server that defines endpoints for dynamic features of the website such as comments, suggestions, and donations.

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A huge thanks to everyone contributing to! The project wouldn’t be possible without you.

Abhishek Upmanyu
Alyssa Holland (Cool-Runningz)
Andreas Bampounis
Ani Karini Muniz Schiebert
Benjamin Altpeter
Daniel Shuy
Denis Müller (WebworkrNet)
Eliott Hauteclair
Faisal Misle
Leah (
Lewin Sieben
Lorenz Sieben
Mæve Rey
Malte Wessels
Milo Ivir
Mohammad Farhan
Nadja Rode
Nathan Bonnemains
Nicolas Formichella (Stig124)
Nishant Mittal
Phoenix Déb
Rafael Audibert
Steffen Grundke

If you have also contributed but your name isn’t on the list yet, we invite you to add it to the AUTHORS file.

Open Source projects used by us


In keeping with the spirit of Open Source, we not only maintain our own Open Source projects but also make heavy use of others for our work.

We are proud to be able to use the following projects for this website. Huge thanks to the authors who have decided to enable others to use their valuable work!

You may find the full license notices for all projects we use here.

Autocomplete.js by Algolia, Inc. (MIT License)

fast-deep-equal by Evgeny Poberezkin (MIT License)

FiraGO by bBox Type GmbH (OFL 1.1)

Free 3 of 9 font by Matthew Welch (MIT License)

Humaaans by Pablo Stanley (CC BY 4.0)

iconmonstr Icons by Alexander Kahlkopf (iconmonstr License)

idb by jakearchibald (ISC License)

immer by Michel Weststrate (MIT License)

JavaScript Cookie by Klaus Hartl, Fagner Brack and GitHub Contributors (MIT License)

json-forms by Ignacio del Valle Alles (Apache License 2.0)

letter-generator by The project (MIT License)

libphonenumber-js by catamphetamine (MIT License)

localForage by Mozilla (Apache License 2.0)

MiniSearch by Luca Ongaro (MIT License)

node-qrcode by Ryan Day (MIT License)

pdfmake by bpampuch (MIT License)

Preact by Jason Miller (MIT License)

preact-compat by Jason Miller (MIT License)

preact-i18n by Synacor, Inc. (BSD 3-Clause)

preact-portal by Jason Miller (MIT License)

react-scrollspy by makotot (MIT License)

React InstantSearch by Algolia, Inc. (MIT License)

Roboto by Christian Robertson (Apache License 2.0)

Spartan MB by Matt Bailey (OFL 1.1)

SpinKit by Tobias Ahlin (MIT License)

Tailwind CSS by Adam Wathan, Jonathan Reinink (MIT License)

Typesense Instantsearch Adapter by Typesense, Inc. (MIT License)

typesense-js by Typesense, Inc. (Apache License 2.0)

World Countries by stefangabos (LGPL-3.0)

zustand by Paul Henschel (MIT License)