I’ll admit this isn’t strictly a Mac oriented post. None the less it is still useful for the Apple//, Mac, and other communities.
When people see something like the title of the post the reaction is pretty much the same as when a politician says “Trust me”. In this case the people operating this organisation have been at it for years. I remember getting books from then in the 80’s or 90’s. They have since updated their technology to support newer formats which can be found on most mobile devices. At the same time they still support simple text files for those of us with cheap piece of @##$% MP3 players which can only read text files. I remember writing a program in Applesoft to read these books on my GS.
These people have been searching for books where the copyright has expired (there are variations of public domain literature which are acceptible as well). As they find them they add the books to their list to be scanned. From there they run the books through Optical Character Recognition (OCR) software. From there it is proof-read by volunteers. Then the books are made available to the public.
Last time I checked the titles I was quite impressed at what they had. For example, they were working on the entire Wizard of Oz series (I think they had five or six of the 40+ books). Their web site claims they have over 33,000 books with links to various organisations resulting in over 100,000 more. Obviously going through the entire list sequentially will take some time.
To check out their web site go to http://www.gutenberg.org/wiki/Main_Page.