YSK: There is a modern free and public domain ebook library app at BookDark.com based on Project Gutenberg where you can search and explore ebooks by authors or tags.
from /r/YouShouldKnow
YSK：在BookDark.com有一個基於Project Gutenberg的現代免費公共領域電子書庫應用，你可以按作者或標籤搜索和探索電子書。