I just want to build math formulas that look nice, no documents, no books. Thanks
closed as too broad by Raaja, egreg, Mensch, barbara beeton, user156344 Mar 9 at 3:37
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(too long for a comment, hence posted as an answer)
[Which] LaTeX version should I download?
and you mentioned that
I just want to build math formulas that look nice.
Your question appears to imply that you expect there to be various manifestations of LaTeX executables, each with various amounts of power or sophistication. But that's not how LaTeX "works".
The two questions you should be asking are: "Once I've downloaded and installed a suitable complete TeX distribution on my computer, which LaTeX document class should I employ?" And, "Which LaTeX packages (if any) should I load in the preamble of my LaTeX documents in order to make typesetting various mathematical expressions straightforward?"
Regarding your first question: It sounds like even a "basic" document class such as
article will do fine. Not knowing what kinds of mathematical typesetting needs you may have, it's not really possible to give an in-depth answer to the second question.