As a non native English speaker,I find letter X fascinating.My mother tongue doesn't have it,unless math is involved.For many years I thought that Xena,Xeon or even Xerox were pronounced with 'ks' rather than 'z'....
In Polish the situation is similar. 'X' does not appear in the Polish alphabet, but is understood as 'ks' (or 'ee-ks' when spelling). For example, 'xero' is pronounced 'kseh-roh' and sometimes written as 'ksero'. I guess it's true for many languages with Latin origns/influences (but I'm not an expert). So 'Xerox' would sound like 'kseroks'. And Windows XP sounds exactly backwards: instead of 'eks pee' you have 'ee-ks peh'.
The letter 'X' was widely used in Polish language 100-200 years ago in loanwords. Nowadays, you can't really see it anywhere, because the language adapted, and the ortography of those words changed. So now you can even see the pronunciation in the writing. A couple of English-Polish pairs of words in writing as an example:
- maximum - maksimum
- xylophone - ksylofon
- text - tekst
In Russian we all pronounce and transliterate as 'kseroks'. And for a non-experienced Russian you'd have to write 'zeroks' so he'd pronounce it correctly.