[texhax] latex --version = pdfTeX ... ?

[Karl Berry]

    Could something that begins with "pdfTeX" really be the version number
    of a latex.exe program? Is latex.exe just a special configuration of
    pdftex?

Yes.  LaTeX is a so-called "format" (collection of macros), not a
separate executable in itself.  http://tug.org/levels.html discusses
such things briefly.  (tug.org is inaccessible briefly due to network
infrastructure work, but hopefully will be back by the time you read this.)

pdfTeX can output DVI, and does so by default when invoked as  
"latex", etc.

    Is there any way to read the latex and/or dvipdfmx version numbers
    at compile time and pass the string(s) to the metadata of the final
    pdf file?

David mentioned \fmtversion for the real LaTeX version.

You can get the "engine" (pdftex) version with, most descriptive,
\pdftexbanner.  Assuming you are using "latex".

There's no (safe) way to get the dvipdfmx version number from within
TeX.  You'd need to extract it with something like
  dvipdfmx --version | sed 1q >fmxver.txt
and then read that external file.

Good luck.  Hope this helps,
Karl