Q:

Proper pronunciation of XeTeX, XeLaTeX

I've always said the first part zeh. Am I saying it correctly?
Related to: What is the correct pronunciation of TeX and LaTeX?

A:

From a  TUG interview with Jonathan Kew, the original author of XeTeX:

DW:     Of course, other readers and I could look at your XeTeX web
  site, but perhaps you can also tell us something about it here. For
  starters, how should I pronounce XeTeX — like Zee TeX? And why did you
  call it that?
JK:     I don't have a strong opinion on the “correct” pronunciation,
  though personally I say zee-TeX. There was some discussion of this on
  the mailing list recently, and it was clear that the “natural”
  pronunciation depends on people's native language — which is fine with
  me.

So for English speakers, I think that 'zee-TeX' (IPA: ['zitɛk] or ['zitɛx]) is indeed the preferred form.
Why 'z' and not some other consonant?
'z'  is the natural way to pronounce other words that begin with 'X' (e.g., xenon, xylophone, Xanadu, xenophobia, Xerox, xylem, to name some that most of us may know.)
Why 'zee' and not 'zeh'?
English speakers actually vary in their pronunciation of words beginning with 'xe', using either 'zee' or 'zeh' (IPA [zi] or [zɛ]).  Some of this variation may be dialectal, but some speakers may in fact have both options freely.  But the 'Xe' in 'XeLaTeX' cannot have the 'zeh' pronunciation.  The reason for this is linguistic.  Since 'tex' and 'latex' are independent words, we interpret 'xe' as  a morpheme (i.e., a piece with independent meaning; that meaning being something like "UTF-8 aware flavour").  This morpheme acts as a modifier (like an adjective) to the 'latex' or 'tex' word.  Because of this, it receives the main stress of the word.   Now English has a general rule of prevents words ending in a vowel to contain one of the so-called 'short' vowels (/ɛ/,/ı/,/æ/,/ʌ/,/ʊ/) So since 'xe' receives stress as a word, and is a syllable that ends in a vowel, it cannot be pronounced 'zeh' and must be pronounced 'zee'.

