OpenTaal (Open Language) aims to create, maintain and distribute free Dutch language files that can be used by free and open source projects. The first milestone (an officially approved word list for spell checking) has been reached. Projects in progress are hyphenation, synonyms and grammar checking.

OpenTaal is also a foundation to support this small group of Dutch language enthousiasts. Help and support is always appreciated.


In 1996 a working group of the Dutch TeX User's Group created a word list for spell checking and hyphenation to be used in TeX software. This list is also used in and has been developed since. At the end of 2005 the Dutch Language Union (Nederlandse Taalunie), the formal Dutch language institute, published a new version of the "Woordenlijst Nederlandse Taal" (Dutch Language Word list, also known as "the Green Booklet"). The new spelling rules laid down in it are compulsory in government and education of participating countries since August, 2006. To comply with the spelling changes, the existing free language files had to be adjusted. At the same time, the opportunity arose to have them certified by the Dutch Language Union. The OpenTaal project was founded to facilitate the collaboration of open source projects in this area.


The project started as an initiative of the government programme OSOSS. From the beginning members of the Dutch TeX Usergroup and of were involved. In the meantime other Dutch branches of open source projects have started to participate. Currently, GNOME-NL, KDE.NL, are newly welcomed partner projects. Anyone who considers the goals of the project important, is welcome to participate.

Instruments of the project

Besides this website (, OpenTaal uses a mailing list and a forum to discuss the working methods and roadmap. Everyone can use these to exchange ideas and discuss. In order to be successful, OpenTaal welcomes any contribution!


Our spellchecker finds our way to the official releases of some applications (Firefox, Thunderbird, within half a year after our release. The datafiles can also be downloaded for our downloads page (on the left, click 'Instructies, then select 'downloads').

Dutch language support

When you are a software developer interested in language support, please check out our list of software related issues. You might be able to enhance language support.