I don't mind that my question is closed, there's no need for any more new answers, plus it means I can keep tinkering with it without people accusing me of bumping the question. But despite being nominated by several people to be re-opened, it has remained closed as "Not constructive" -- and I was wondering why.
I've reworked the title a little bit, to give it a shot at staying open.
The red flag, in my mind, was the title. It seemed really open ended, even though when you read the question, it's quite specific. I've narrowed the title, but I haven't changed the actual question you've asked.
I've also re-opened the question, and I agree that it's on topic, constructive, and answerable.
Your question also has another problem: A lot of 'shopping'-esque answers. It's as if people take this to mean, "What should I use to install PHP?" Instead of the question that was actually asked. I removed the answers that didn't address the question at all (since they are, by definition, "Not an answer"). This may also be why your question was closed by the community -- it begat bad answers.
As far as Shog9 agreeing that it should remain open, there are two things you should realize:
Moderators disagree amongst each other regularly. We try not to fight in front of everyone, but we do have instances where we disagree. You can think of us more like the Greek Gods than The Circle.
Shog9 is a member of the Community team (the "Community Manager", as of this writing). While he is 'our boss' (if any such thing exists), he generally tries not to get in the middle of Stack Overflow moderation efforts unless he really needs to (examples include: moderators screwing up big time). In this case, there's no need to have Shog9 get involved, although he could if he really wanted to.
Why is this question “Not constructive”?
Because Wooble, LittleBobbyTables, Jocelyn, ldav1s, and Servy thought it was. If five users each with over three thousand reputation think something is not constructive, then it probably is, which is why it was closed.
But despite being nominated by several people to be re-opened,
The question only has 2 reopen votes (at the time of the writing of this answer).
What's weirder is that Shog9 ♦ verified that the question was appropriate for Stack Overflow. So why was it closed, and why has it remained closed?
Because people can disagree with each other. Also, that was a long time ago. Things can change in two years.
I'm going to chime in an answer not to say that it is on the line, but to say why it's on the line.
Current title stands at: "What are the technical differences between the Thread Safe and Non Thread safe PHP Windows Installation Packages?" This is definitely the kind of title that gives a question a good chance.
If there is one or a few differences, then it's a constructive question. If there are many, many differences, then it's not a constructive question. Here's the beauty: The OP (or title editor) doesn't know which it is at the time of asking. The community experts do. It is a posteriori not constructive. Therefore it is a good question with good research effort, but might be honorably closed as not constructive anyway. (Note the good research effort may be the editors', not the OP's. Doesn't matter.)
My answer here explains dealing with questions in which it's not apparent whether it will be a good question or not.