The team over at thePHP.cc recently published an ebook entitled PHP 7 Explained, "Everything you need to know about the next generation."
A few weeks back, I received an email from them stating "As a token of our appreciation for your involvement in the PHP community we would like to gift you a copy of our eBook." Yay, free stuff! Since I'd gotten it free, and it's of timely use to the PHP world, I decided to publish a formal review.
Disclaimer: I was not asked to write a review, although the authors did ask for feedback. The only compensation I receive for this review is the book itself, which was sent without the expectation of a review. Also to the authors, yes feel free to quote portions of this review on the books site as long as it's credited.