The situation isn't nearly as cut and dried as Wikipedia might make it sound.
For example, under US copyright law:
§ 117 . Limitations on exclusive rights: Computer programs
(a) Making of Additional Copy or Adaptation by Owner of Copy.—Notwithstanding the provisions of section 106, it is not an infringement for the owner of a copy of a computer program to make or authorize the making of another copy or adaptation of that computer program provided:
(1) that such a new copy or adaptation is created as an essential step in the utilization of the computer program in conjunction with a machine and that it is used in no other manner,
I doubt that this was the intent of that bit of law, but this does give some wiggle room for the site owners to at least argue that what they/their users are doing is legal.
Of course, copyright law does also vary (somewhat) with locale. Depending on where their servers are located, it's at least possible that the law there is somewhat less strict.
There's another technicality that figures in here as well: most of copyright law is more or less aimed at a situation such as another publisher taking a work and selling the misappropriated work for their own profit. To do that, the person/group who's misappropriated the work normally has to make copies, then offer them for sale--and much of most copyright law is written to prevent that.
In a case like this, where the site isn't actually making copies, but is merely placing the work in a situation where somebody else can make copies, many of those provisions sort of fall apart. So, the basic rights under US copyright law are:
§ 106 . Exclusive rights in copyrighted works
Subject to sections 107 through 122, the owner of copyright under this title has the exclusive rights to do and to authorize any of the following:
(1) to reproduce the copyrighted work in copies or phonorecords;
(2) to prepare derivative works based upon the copyrighted work;
(3) to distribute copies or phonorecords of the copyrighted work to the public by sale or other transfer of ownership, or by rental, lease, or lending;
(4) in the case of literary, musical, dramatic, and choreographic works, pantomimes, and motion pictures and other audiovisual works, to perform the copyrighted work publicly;
(5) in the case of literary, musical, dramatic, and choreographic works, pantomimes, and pictorial, graphic, or sculptural works, including the individual images of a motion picture or other audiovisual work, to display the copyrighted work publicly; and
(6) in the case of sound recordings, to perform the copyrighted work publicly by means of a digital audio transmission.
So, let's consider these one at a time:
- The site isn't really reproducing the copyrighted work, except to the degree that (for example) a web cache server held all or part of a copy of the work.
- It doesn't appear that they're preparing any derivative works.
- I don't see anything indicating that they're claiming to transfer ownership, lease, or lend the work ("lending" carries the specific idea of the item being returned, not being permanently transferred).
- through 6. clearly don't apply to an operating system (nor probably to any computer program).
There's another provision in §108, that says:
(d) The rights of reproduction and distribution under this section apply to a copy, made from the collection of a library or archives where the user makes his or her request or from that of another library or archives, of no more than one article or other contribution to a copyrighted collection or periodical issue, or to a copy or phonorecord of a small part of any other copyrighted work, if—
(1) the copy or phonorecord becomes the property of the user, and the library or archives has had no notice that the copy or phonorecord would be used for any purpose other than private study, scholarship, or research; and
(2) the library or archives displays prominently, at the place where orders are accepted, and includes on its order form, a warning of copyright in accordance with requirements that the Register of Copyrights shall prescribe by regulation.
This was originally intended to apply to things like a copying machine at a library. If I go to the library and make a copy of something on the copying machine, I'm responsible, not the library. If (for example) I'm disabled, and ask one of their employees to make the copy, I'm still responsible for it, not them.
The question in this case would be whether the web site qualifies as a library or archive. The fact that the site at least appears to be open to the general public seems to let it meet the legal requirements to qualify.
This isn't just stretching a technicality to apply to the current situation either. The basic idea is fairly simple: a library or archive should be free to provide source material, and even provide copying equipment to their patrons. As long as they take the steps required by the law to tell/remind the patrons that wholesale copying may infringe a copyright, it's the patrons, not the library/archive, who are responsible for the copyright infringement. That seems to fit extremely well with what's happening here.
That means just about any infringement that might occur would have to be on the part of the person doing the downloading, not the web site itself. Here (again) the first point brought up from §117 still (at least potentially) applies--it may still be legal. Of course, there's also the possibility that the downloader is simply somebody who (at some point in the past) actually bought a license to the program they're downloading/using. In that case, if that license hasn't ever been transferred to anybody else (and most contain provisions saying you can't transfer them) then the user is probably still authorized to install and use it (e.g., most older license agreements don't contain any limit on how long the license lasts).
Bottom line: as I originally said, the situation here isn't really cut and dried. If the site were to be sued and the case were being heard in a US court, I'd guess there would be better than even odds that the court would shut down the site--but honestly, only a little better than even odds. I wouldn't come as a huge surprise to me at all if the site could successfully defend themselves as being a publicly available archive, and any copyright infringement was the responsibility of the users, not the archive itself.
As far as other countries go: in theory, copyright law is fairly uniform between a large number of countries. There are quite a few international agreements (starting from the Berne convention of 1886) about copyrights and copyright law. In reality, however, there's still quite a bit of variation--but I'd say the US tends to favor copyright holders at least as much as almost any country, so if such a suit were brought in another country, the chances of the site being held responsible would be no greater, and in many cases would be much lower.