Well, I think we all expected a "modern LaTeX" based on the title, not something that's much closer to a PDF producer than a LaTeX equivalent. The title is the issue.
I might want to use LuaTex, if I knew what it was. It seems they can't be bothered to actually say what it is in their website, in any of their links, or in the introduction chapter of their manual.
I therefore take it that no-one who actually writes ever uses it.
Not sure if you're trolling, but luatex.org explains it right in the first paragraph:
LuaTeX is an extended version of pdfTeX using Lua as an embedded scripting language. The LuaTeX projects main objective is to provide an open and configurable variant of TeX while at the same time offering downward compatibility.
No, I'm not trolling. I don't know what pdfTex is either. Why on earth are you telling me what a project does in terms of another project I'm not familiar with?!
Edit: that's what I meant by "none of their links", the pdfTex page doesn't say what it does either!
Maybe it's not what you intended, but to me you seem to be proud of your ignorance about a piece of software that's part of computer science history. Instead of writing that comment, you could have learned something by reading about TeX on Wikipedia.
I know what TeX is. I should know what luatex is because I've been to their website, read through some links and even read through the introduction to their manual, and still I don't know.
And just listen to yourself: if I want to know what luatex is I shouldn't find out on their own website, I should have to go to Wikipedia?!
Do you know what it is? You've managed to reply to me twice and in neither of those replies have you simply stated: "luatex is software that does x. You'd want to use to to do y."
Coming from a position such as yours, here's how I interpreted it:
pdfTex will take TeX input and output PDF (and apparently other file formats as well).
LuaTeX should do the same (being a drop-in replacement), the difference being that it can also use Lua scripts to control how the output is formatted (versus everything being written in TeX).
Ok, well, maybe I don't understand TeX at all, because I thought that's exactly what it did.
EDIT: Ahh, wait, I have it! When they say "extension" they mean "implementation"! They actually replace TeX as an engine. Is that right? So, luaTex is just an implementation of TeX written in Lua?
Because people do not care about their TeX interpreter. Today, nearly every LaTeX writer uses pdfTex. If they switch to luaTex nothing changes, because luaTeX is (intended to be) fully backwards compatible. If you start writing your own packages, then luaTex becomes interesting.
