It is, for now.

This website gives you the ability to build a vocabulary the most used 5000 nouns in German language. You will be able to practice Der, Die, Das freely as you increase your own vocabulary. You can add new words into it and focus on the hardest words, if you prefer.

In the new future, new options may be added to use the service as a full vocabulary tool. New types of users may be added as well.

As an early bird on DerDieWhat.com you get the opportunity to use it as you please.

In a matter of months however there may be a small fee applied to registered users, to cover hosting, improvement and maintenance costs.

Until then, feel free to use this resource and keep practicing.