Professional.Wiki provides services and solutions on top of MediaWiki. MediaWiki is the software that powers Wikipedia. It is used by many companies for knowledge management.

We are a group of MediaWiki professionals. Our expertise is extensive and unmatched in several areas by anyone else. We are actively involved in the MediaWiki community and have an established track record.

Our Values

The focus of our business is long term. We look for win-win collaborations with our customers. In all our work we care greatly about quality and sustainability. We want to do things the right way. This includes zooming out and coming up with holistic solutions.

Our Mission

We believe that enterprise MediaWiki is very underused for knowledge management. Our mission is to help companies manage their knowledge better. To achieve this we work on raising awareness about how enterprise MediaWiki can deliver value. We also strive to enhance the software and to be a reliable partner for enterprises.

Our Team

Professional.Wiki - Karsten Hoffmeyer

Karsten Hoffmeyer

Organizational director

Karsten is organizational director of Professional Wiki and lead administrator with extensive MediaWiki experience. He has been managing wikis using MediaWiki and related extensions since 2009 and is the Semanic MediaWiki project manager. During this time he has provided MediaWiki hosting and services to many companies and organizations across Europe. Karsten has been working at WikiHoster.net since 2011, a MediaWiki hosting and consulting company which he continues to run for hosting. Karsten is an expert in the field of wiki creation, configuration and administration and is passionate about providing reliable and sustainable work.

Professional.Wiki - Jeroen De Dauw

Jeroen De Dauw

Technical director

Jeroen is technical director of Professional.Wiki and lead developer with extensive MediaWiki experience. He has been developing for MediaWiki and related extensions since 2009 and is one of the two Semantic MediaWiki maintainers. During this time he has worked for several companies across the globe, including Google and the Wikimedia Foundation. From 2012 to 2019 Jeroen worked for Wikimedia Deutschland where he was part of the original Wikidata team and held the position of Software Architect. Jeroen has a passion for software design and quality, agile/lean processes and getting things done.

Tobias Oetterer

MediaWiki expert

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

Iván Hernández-Cazorla

MediaWiki expert

Iván is specialized in cultural heritage and digital humanities. He has been providing both MediaWiki and Semantic MediaWiki services for multiple years. He is active in the community and is familiar with Wikidata.

Stephan Gambke

MediaWiki expert

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.

Peter Grassberger


Peter is a well rounded developer with several years of MediaWiki experience. He has contributed to Semantic MediaWiki, Maps and several other MediaWiki extensions.

Wouter Rademaker

MediaWiki expert

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

MediaWiki expert

This could be you!

Are you someone of integrity that is passionate about and skilled with wikis? If so, contact us for possible collaborations.

Check our Partner Program if you want to help us find clients.

Our Passion

Professional Wiki - MediaWiki development


MediaWiki (MW) is a free, open-source software – the wiki software that powers Wikipedia and many more projects – that lets you collectively and directly edit content.

MediaWiki is a full-fledged framework, in conjunction with a lot of spin-off extensions, that can turn a website into a powerful and flexible knowledge management system for best collaboration. All information created within MediaWiki can easily be structured and published allowing users to benefit from it.

Professional Wiki - Semantic MediaWiki development

Semantic MediaWiki

Semantic MediaWiki (SMW) is a free, open-source extension to MediaWiki – the wiki software that powers Wikipedia and many more projects – that lets you store and query data within the wiki's pages.

Semantic MediaWiki is also a full-fledged framework, in conjunction with many spin-off extensions, that can further refine a wiki into a even more powerful and flexible knowledge management system. All data created within Semantic MediaWiki can easily be exported or published via the Semantic Web, allowing other software systems to use this data seamlessly.

Our Projects

Maps MediaWiki extension


Maps is the MediaWiki extension for visualizing geographical information. It is used on thousands of wikis. Jeroen developed it in 2009 using funding from Google and maintained it ever since.

Chameleon skin for MediaWiki


Chameleon is a popular MediaWiki skin. It uses the Bootstrap 4 framework and is highly customizable. Stephan created it in 2013 and it is now maintained by Professional Wiki.

Semantic Bundle for MediaWiki

Semantic Bundle

Semantic Bundle is a bundle of MediaWiki extensions. It makes it easy to install Semantic MediaWiki and associated extensions in one go.

Professional Wiki - WikiHoster.net


WikiHoster.net is a wiki hosting service operated by Karsten since 2011. It is the precursor to the hosting services provided by Professional Wiki.

Professional Wiki - EiKoLo


eiKoLo is a contact management solution for small organizations. Track relations with your customers via an in-wiki database.

Our Contributions

We have created several MediaWiki extensions and contributed to many more. These contributions include development and testing of new features, creating and enhancing documentation, providing translations and supporting people on the mailing lists.

MediaWiki extensions:

  • SubPageList
  • ID Generator
  • Nuke
  • Page Forms
  • Upload Wizard
  • RSS
  • GraphViz
  • Maps
  • Translate
  • Widgets
  • Create Page
  • Wikibase
  • Survey
  • Contest
  • Push
  • Live Translate
  • LocalizationUpdate
  • Arrays
  • Spark
  • Gitweb
  • Github
  • FolkTagCloud
  • SphinxSearch
  • Wiki Object Model
  • Validator
  • Did You Know
  • Include WP
  • Flagged Revs
  • AmazonPartnerLink
  • DateDiff
  • SyntaxHighlight GeSHi
  • Summary Cards

Semantic MediaWiki extensions:

  • Semantic MediaWiki
  • Semantic Result Formats
  • Semantic Compound Queries
  • Semantic Extra Special Properties
  • Semantic Signup
  • Semantic Forms Inputs
  • Semantic Forms Select
  • Semantic Graph
  • Semantic Image Annotator
  • Semantic Tasks
  • Semantic Internal Objects
  • Semantic Cite
  • Semantic Scribunto
  • Semantic Breadcrumb Links
  • Semantic Meta Tags
  • Semantic Interlanguage Links
  • Semantic Glossary
  • Semantic External Query Lookup
  • Semantic Notifications
  • Modern Timeline

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!