Originally Posted by Kostaz 
I had the impression that Project Gutenberg was just about copyright-free ebooks, is there more to it?
Yes, it's primarily about copyright-free ebooks. They partner with
Distributed Proofreaders, who now provide most of PG's proofed and formatted content via crowdsourcing. There is also
LibriVox, which is a project to record audio books from the public domain.