Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
I take part in the free textbook project “Mathe für Nicht-Freaks” (German textbook for beginners of mathematics). We are looking for co-authors! When you want to participate in this project, feel free to contact us. You will help a lot of students!