Here are some links to interesting websites which offer DRM-free ePub-books.

Gutenberg.org

Gutenberg.org is one of the most famous sources for free ePub eBooks. They offer about 30,000 books in many different languages.

Website language: English

Visit Gutenberg.org

Manybooks.net

Manybooks.net offers more than 26,000 free eBooks in many different languages. Definitely a place to go when you are searching for free eBooks.

Website language: English

Visit Manybooks.net

Mobileread.com

Mobileread.com offers more than 1,800 free ePub eBooks. Most of them are English but there are also many in German. The Mobileread.com community is very active, so there are added several new books almost every day.

Website language: English

Visit Mobileread.com

Mendele.co.il

Mendele.co.il is the first website which offers ePub eBooks in Hebrew.

Website language: Hebrew

Visit Mendele.co.il