Some more book-related #alternatives:
https://inventaire.io - Community for swapping books powered by libre software & WikiData, follow them on here at @inventaire
https://libreture.com - eBook storage site with social features, follow them on here at @kevinbeynon
https://openlibrary.org - Huge non-profit online library with downloads for PD books and lending for non-PD titles.
https://calibre-ebook.com/ - Open source eBook organiser/editor and format converter
#Books #eBooks #Literature