What I’ve built here is a structured edition — the parsing, reconstruction, linking, indexing, etc. I haven’t published a formal license for that yet.
For casual or small-scale use there’s no issue at all. For bulk use (e.g. dataset / training / redistribution), I’d prefer people get in touch so I can figure out a sensible way to support that.
If you live in the U.S. I recommend you read No Sweat of the Brow Copyright: https://www.gutenberg.org/help/no_sweat_copyright.html
They only release books that are in the public domain.
Not necessarily. Project Gutenberg does provide some works still under US copyright, such as F. P. Walter’s 1999 translation of Twenty Thousand Leagues Under the Seas: https://gutenberg.org/ebooks/2488