The a in the name Jacques is pronounced as in the word father.
The a in the name Jack is pronounced as in cat.
Something I find interesting is that Americans say the a in the word taco (a word borrowed from Spanish) with the a as in father, that is, [ɑː], but English people say the a as in cat, [æ]. Different dialects approximate the Spanish [a] differently.
Yes they're slightly different in theory, but not in any way that would prohibit mutual understanding. Besides, if you're telling anyone about this library you're most certainly going to spell it out anyways.
I was confused reading people say that Jacques is pronounced the same as Jack, so it does seem like mutual understanding is inhibited.
It's just like how, even though Johann is a German name (though borrowed from Latin), I know to pronounce it in English not as [dʒoʊhæn] (the naive English pronunciation), but as [joʊhan], which is similar to the German pronunciation, [johan].
My original sentence repeated the same word twice as a typo. It was this:
> I was confused reading people say that Jacques is pronounced the same as Jacques.
I realized my mistake and edited it to this:
> I was confused reading people say that Jacques is pronounced the same as Jack.
If we'd been discussing the words "chick" and "chic," I might have accidentally written:
> I was originally confused reading people say that chick is pronounced them the same as chick.
Then I'd realize my error and edit it to:
> I was originally confused reading people say that chick is pronounced them the same as chic.
That doesn't mean I actually pronounce "chick" the same way as "chic" and it doesn't make the words interchangeable in the dialect I speak. "Chic" is pronounced like "Sheikh," referring to the Arab leader, or like "Sheik" from the Legend of Zelda. I'll be confused if you say "a baby Sheikh" instead of "a baby chick," and if you say "chick fashion" instead of "chic fashion" I'll be thrown off but realize you meant "chic."
> mix up without notice aren't interchangeable.
Sometimes I have accidentally written "chick" when I wrote "chic" due to autocorrect, just not during this conversation.
Regardless, I guess I can't make you believe me when I say what sounds natural to me. Ignore what I say if you really want. The fact that you insist that I say the two names interchangeably does not make it so.