I got my OpenBSD account as a developer in 2002, more than 10 years ago. Over this time, quite a number of OpenBSD-related books have been published. Some were actually good, but many were not and were full of factual errors. I kept asking myself (and others) why these authors never approached us for fact-checking before publishing.

I have known Michael for a long time as well—many, many years. Both of us frequently visit BSD-related conferences, and we often end up having a beer together, which is always fun. I did read the first edition of Absolute OpenBSD when it was published, a long time ago, and quite frankly, I don’t remember anything from it. That’s a good thing in this case, because I would have remembered if it had been bad. I have recommended it as an introduction to OpenBSD a couple of times.

So when Michael approached me asking whether I would be willing to fact-check the second edition of Absolute OpenBSD and provide feedback, I happily agreed.

I have done the reading on airplanes almost exclusively, and one day when I had to fly to Helsinki, I had no chapters left to read. That ended quite badly, with a WWII bomb leading to Frankfurt Airport being closed for a while, the aircraft I was supposed to fly in being identified as defective, and, of course, bad weather causing massive delays. While that was coincidence, of course, the rumor was out that I couldn’t fly without a chapter from Michael.

Now that I am long done with reviewing, I have survived many flights without chapters to read over, but Absolute OpenBSD made long hours up in the sky much more enjoyable for me. Michael has a writing style that I really like—snatchy, funny, and still precise and to the point. Don’t skip the footnotes!

In the end, I contributed only a tiny share to this book, but I enjoyed doing so a lot. I hope you enjoy reading it as much.

Henning Brauer

OpenBSD PF developer