Recommendation: folkscanomy

«A mind needs books like a sword needs a whetstone.»
Unknown

I’ve written about the Internet Archive before (e.g., here) — it’s a website that has a huge collection of books, movies, etc. Recently I stumbled upon the folkscanomy subpages ( https://archive.org/details/folkscanomy ). Not really sure what they are, only, there are lots and lots of interesting books there. Luckily, there are collections based on topic, e.g.:

There are also individual collections that might be interesting, e.g.:

They also make it easy to find … uh, interesting (NSFW) books. Just look at what they want to deemphasize: https://archive.org/details/deemphasize

BTW, if you are interested in mangas or adult comics, go for the .cbr or .cbz versions. They are essentially lossless compressed directories with good quality images — .cbr are actually .rar files, .cbz are actually .zip files. For .rar files, you need an app like «The Unarchiver». Reason being that the pdfs are lossy compressed. You do notice it with normal books, but it is devastating on images (e.g., manga pages). Just uncompress the .cbr or .cbz files, then convert the images into PDF (e.g., merge them into a PDF with PDFExpert or Mac OS Automator).

Happy reading.