Higher Order Perl
Mark Jason Dominus’s excellent Higher Order Perl is now available for free in PDF and MOD formats. This is the kind of book I like to read on paper, though.
Update (2014-12-02): Mark Jason Dominus:
Would the book have made more money if it were not available as a free download? We can’t know for sure, but I don’t think so. The book has always sold well, and has made a significant amount of money for me and for Morgan Kaufmann. The amount I made is small compared to the amount of work I had to put in, just as Greenspun said, but it was nothing to sneeze at either. Even now, ten years later, it is still selling and I still get a royalty check every six months. For my book to have lasted ten years is extremely rare. Most computer books disappear without a trace after six months.
[…]
So my conclusion is, Greenspun’s advice was exactly correct. As an author, you owe it to yourself to make your book available to as many people as possible. And the publisher may agree, so be sure to ask.
