VDM Publishing itself specializes in print of demand of various people's theses. Something like a vanity press, but as a bonus the authors don't have to pay anything, and VDM takes 80% of the earnings. These are sometimes weak offerings, and often available to download for free, but the practice itself is nothing out of the ordinary. So VDM Publishing's authors really are authors, but of theses and similar.
Alphascript and Betascript Publishing (and Fastbooks, in German) are the Wikipedia-aggregation publishers, imprints of (i.e., marketing names for) VDM Publishing. They entirely avoid the expense of looking around for theses and approaching authors, instead simply sucking related articles from Wikipedia. The book titles are goofy as a result, there are no authors, but the costs are miniscule. With a pool of a few hundred million unsuspecting customers exposed via Amazon and others, it just takes one out of every thousand to misstep to make for a profitable business, one that basically makes money off of people's ignorance. At least cigarettes offer nicotine in addition to lung cancer. To the people who argue, "well, you should just be aware of the problem", this sounds to me like smug "I'd never get fooled, I'm so smart" blather to me. Would you say the same if you were the one who bought such a book? Maybe you would, maybe you're the type of person who blames themselves for getting conned, but I blame the con man.
Speaking of blather, I'm sad that no one's commented on one of the Betascript "editors" names is Lambert M. Surhone, which the Internet Anagram Server turns into "Blather Summoner" as the first match, a great fit for the products offered. My original article on VDM mentions this and other fine anagrams.
One ray of sunshine is that giving these books 1-star ratings on Amazon does kick them down the lists. For example, I gave 1-star ratings to a number of their so-called books on Transnistria on Amazon. 3 of their books were the top three books listed on this subject on Amazon before I rated them, now they appear further down the list.
As far as other firms go, AbeBooks indeed sells Alphascript Publishing (45333) and Betascript Publishing (953) books. Oddly, they are all the same price (vs. those on Amazon, which appear to be priced by the pound), from a few different shops. Borders, to their credit, does not carry any Alphascript or Betascript books. Barnes and Noble does.
I will say one thing for VDM, they do add a tiny bit of value (beyond the wacked titles) in their choices of covers, e.g. this peculiar one for a book on legal disputes about Harry Potter.