GeezerVison is showing professional.wiki — About

Why we’re here

Creating a modern wiki experience on top of the software that powers Wikipedia.

MediaWiki is a powerful open-source software platform that powers hundreds of thousands of wikis. Professional Wiki provides professional MediaWiki consulting services and MediaWiki hosting. We make MediaWiki more useful for businesses and organizations.

We maintain Semantic MediaWiki and build NeoWiki, an open-source extension for structured data in MediaWiki, now in beta. We also invest in Wikibase.

With ProWiki we provided the first truly modern MediaWiki experience. Gone are the days of needing to assign your IT staff to maintain a new software stack. You configure your wiki from a web interface, with no server administration needed.

Our Expertise

MediaWiki

Semantic MediaWiki

Wikibase

NeoWiki

The Company

15+

years of experience

300+

clients helped

250+

wikis hosted

48000+

code changes

Professional Wiki GmbH is a Berlin-based company with an international team that serves international clients.

We are MediaWiki veterans with expertise that includes MediaWiki hosting and MediaWiki software development.

Professional Wiki has made significant contributions to MediaWiki, Semantic MediaWiki and Wikibase. Our MediaWiki developers created over 40 MediaWiki extensions and our Wikibase developers created over 8 Wikibase extensions. We also write a lot of MediaWiki documentation.

We are a customer-focused agile company. We value professionalism, quality and sustainability.

YouTube

GitHub

Our History

2009

Our Humble Beginnings

Our founders attend their first SMWCon. Jeroen creates the Maps extension.
2010-2018

We Level Up

We become maintainers of Semantic MediaWiki. Jeroen joins Wikimedia Deutschland as one of the original developers of Wikibase and Wikidata, and is promoted to Software Architect. Karsten launches WikiHoster.net.
January 2019

Founding of Professional Wiki

We start collaborating formally to deliver next-level MediaWiki services.
May 2022

ProWiki Launches

We launch ProWiki, the most modern and user-friendly MediaWiki hosting platform.
October 2026

NeoWiki Beta Launches

We release the first public beta of NeoWiki, our open-source extension for structured data in MediaWiki.

Meet the Team

Jeroen De Dauw

CEO & CTO

Jeroen created Wikibase, maintains Semantic MediaWiki and is credited as one of MediaWiki's creators.

Jeroen is a software craftsman with deep expertise in software architecture, testing, and quality. He occasionally posts on his developer blog.

Jeroen started working with MediaWiki in 2009 and has since assisted companies across the globe, including Google and the Wikimedia Foundation.

In his spare time, Jeroen enjoys beach volleyball, board games, and reading.

Karsten Hoffmeyer

CFO & MediaWiki Expert

Karsten is a MediaWiki veteran with deep and broad MediaWiki usage expertise.

Karsten has set up 100s of wikis and is one of the most active editors of documentation on MediaWiki.org and Semantic-MediaWiki.org.

Karsten got involved with MediaWiki in 2009. In 2011, he launched WikiHoster.net. Karsten has spoken at several Semantic-MediaWiki conferences (SMWCon).

In his free time, Karsten enjoys caring for plants, reading books, taking walks, and using wikis.

Morne Alberts

MediaWiki Developer

As the maintainer of the popular Chameleon theme, and (co)creator of a dozen extensions, Morne is an experienced MediaWiki developer. He has a passion for automation, testing and sustainable solutions.

Alistair Kim

MediaWiki Developer

Alistair is a developer and designer with almost a decade of MediaWiki experience. He created and maintains the Citizen skin and is known for styling wikis like the Tolkien Gateway and the Star Citizen Wiki.

Tobias Oetterer

MediaWiki Expert

Tobias is a well-rounded MediaWiki expert and an experienced wiki administrator. He has set up multiple wikis, created MediaWiki extensions, and has been involved in the Semantic MediaWiki community for many years.

Stephan Gambke

MediaWiki Developer

Stephan is a veteran MediaWiki developer. He created several MediaWiki extensions and is the author of the popular Chameleon skin. Stephan has been involved with the MediaWiki and Semantic MediaWiki communities for over a decade.

Wouter Rademaker

MediaWiki Expert

Wouter has been working with MediaWiki for over 15 years. His experience includes constructing and maintaining wiki farms, among which is an integrated multi-language farm, system administration and Semantic MediaWiki.

Our Development Portfolio

View our open-source MediaWiki projects.

Customer Testimonials

"Professional Wiki provided Rhizome with competent and timely custom development work. Making use of all the tools that are available to open source developers today, the team built extensions that follow modern software design guidelines, are easy to install, configure, and maintain, and include good documentation and automated testing. Quite unique in the MediaWiki space!"

Dragan Espenschied / Preservation Director, Rhizome

"I had the pleasure to work with Jeroen at Wikimedia Deutschland. Jeroen is one of the most productive and passionate developers that I know. Without Jeroen, Wikidata would not have such a rich range of functions and would be built on a less flexible, lower-quality codebase and architecture. Jeroen has in-depth knowledge and broad experience about clean code and software architectures. I have always appreciated his professional attitude, collegial and reliable manner. He is an absolute win for any team and project!"

Abraham Taherivand / Executive Director, Wikimedia Deutschland

"Jeroen was working on Semantic MediaWiki and was one of the original developers on Wikibase at Wikimedia Deutschland. I had the pleasure of working with Jeroen for many years and have rarely found someone as dedicated as him towards the quality of the software he is working on."

Denny Vrandečić / Head of Special Projects, Wikimedia Foundation

"We were lucky to have had multiple opportunities to work with Professional Wiki and were consistently impressed by their expertise and commitment to quality. They deliver outstanding results and provide back to the open source community. Professional Wiki is professional, knowledgeable, and dedicated to delivering top-notch software. Their passion and experience in software architecture and clean code are evident in every project they take on. We highly recommend Professional Wiki for any project in the MediaWiki/Wikibase space."

IP Squared and Digital Werktuig / on Automated Values and Wikibase EDTF

Professional Wiki is able to satisfy all your needs as single provider serving high quality holistic customer-focused solutions. Just get in touch with us!