About me

Hi! I'm an open source developer and software engineer from Germany, interested in web related technologies, API and framework design, software security and distributed systems. Open source is also a big part of my job at GWDG, where I maintain and develop various free software based solutions that directly or indirectly benefit the academic community.

Before we start: Do not contact me directly for job offers or support requests. I do not offer direct support (payed or free) for any of my open source projects. If you need help or want to report bugs, please use the corresponding mailing-lists or issue-trackers. Security related issues are an exception from this rule, though. Feel free to contact me directly via email if you find a bug that should not be discussed in public.

Open Source Projects

Incomplete list of projects or ideas that I can call my own. There are a lot more small projects, contributions or experiments not worth mentioning here. Most can be found on github.

Bottle - Python Web Framework

Bottle is a fast, simple and lightweight WSGI micro web-framework for Python. It is distributed as a single file module and has no dependencies other than the Python Standard Library.

• bottlepy.org
• github.com/bottlepy/bottle
• pypi.org/project/bottle

Multipart - Python parser for multipart/form-data

This module provides fast and predictable parsers for RFC-7578 multipart/form-data, both low-level and non-blocking for framework authors, and easy to use high-level wrappers for WSGI application developers. Starting with Python 3.11 it is mentioned on docs.python.org as an alternative to the deprecated cgi.FieldStorage parser.

• github.com/defnull/multipart
• pypi.org/project/multipart
• Benchmarks

Pixelflut - Multiplayer canvas

Pixelflut is a very simple (and inefficient) ASCII based network protocol to draw pixels on a shared screen. It works great as a group activity for novice programmers due to it's low entry barrier, or as an interactive and very chaotic art installation at hacker events. If you have a beamer or LED wall, a solid network, and a bunch of hackers, give it a try. It's fun.

The idea was born at EasterHegg 2014 and evolved into a recurring part of most CCC events since then. Pixelflut really developed it's own live and now there are dozens of server and client implementations available. Reddit came up with a similar idea in 2017 with /r/place and scaled it to thousands of global users.

• cccgoe.de/wiki/Pixelflut
• github.com/defnull/pixelflut

Fediwall - Social media wall for the Fediverse

Fediwall is a social media wall made for Mastodon. Follow hashtags or accounts and show the most recent posts in a self-updating, screen filling and visually pleasing masonry grid layout. Put it on a large screen and showcase community feedback or social media reactions while hosting your next big event, or use it to look at cat pictures all day. Your choice.

• fediwall.social
• github.com/defnull/fediwall

Misc and More

• contexter - A better contextlib for python
• pycdstar3 - Python API client for GWDG CDSTAR
• More on github ...

Work Related Projects

Even though most of my work related projects and contributions are also open source, I won't list them here. If you are interested in what I do for a living, just ask.