Authoritative publishers of German dictionaries include Collins, Bertelsmann, Duden and Kempcke. The Austrian Federal Government publishes the "Österreichisches Wörterbuch," a dictionary based on the Austrian version of the German language.
The Duden is one of the most authoritative and best-known dictionary in the German-speaking world. It takes its name from Konrad Duden, a linguist who published the first version of the dictionary in 1880. Since its first publication almost 200 years ago, the Duden dictionary is considered to have set the foundations of German spelling and grammar rules. The site duden.de has an online version of the dictionary with mobile apps available for download.