For some years, the second edition of my book The Machinery of Freedom has appeared to be out of print—shown on Amazon only at high prices from third parties who presumably had stock left over. I just spoke with someone at the publisher (Open Court), who claimed that it had never been out of print, despite Amazon not having it, and referred me to their web page. The book is indeed there, and presumably can be ordered.
Checking with the Wayback machine, I found that it was on their web page during the period when I believed, and various people told me, that it was effectively unavailable—but during much of that time it was listed as "usually ships in 4 to 6 weeks," which raises some question as to exactly what "in print" means. If anyone orders it, let me know whether it arrives in some reasonable length of time.
One reason the question is of interest to me is that I plan to do a third edition. If it has stayed in print, then Open Court still has the copyright and a new edition has to be either with them or with their permission. If it was out of print then, under my contract, the copyright reverts to me. It is not yet clear whether they would be interested in publishing a third edition or, if not, willing to permit me to do so.
I should add that for those who are happy reading books on their screen, the pdf of Machinery is available for free on my web page.