The Implementation of Functional Programming Languages by Simon Peyton-Jones is a classic work in the area of functional programming language implementation. Sadly, it is also out of print, and hardcopies of the book are hard to find and are generally very expensive. The author, who is completley unaffiliated with this repository, provides a scanned version of the printed book on his website. (Thank you, Simon!)
The scanned version is certainly nice to have but leaves a lot to be desired in terms of comfort of reading and flexibility. You can't copy and paste, for example. I have OCR'ed the text (see the pages_txt directory) and have typeset the preface, Chapter 1, and the first section of Chapter 2 for my own enjoyment.
It is unlikely that I will typeset the entire book—or even half of it. I have already done the hard part of obsessively reproducing the typography and layout. It would only take a dozen or so people typesetting a couple of chapters each to complete the whole thing, so pull requests are certainly welcome.
Thank you again to Simon and to the many other scholars who have provided me countless hours of pleasure being lost in your books.
Sincerely,
Robert Jacobson