Acho que depende principalmente de você, pois essa pergunta não foi respondida definitivamente antes :
Citando esta postagem no fórum :
hehehe ... it remembers me the old sound card test when you heard Linus saying 'hello, this is Linus Torvalds and i pronounce linux as linux ...' ... Let me just say that the pronounciation is up to you ... even CentOS developers pronounce it one time Saintoss and Saint-O-S next time ... Because of the capitals letters i pronounce it Saint-O-S ...
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Capitalisation make no difference to pronunciation, so if you wanted "Sent Oh Ess" or "Kent Oh Ess" you would need to spell it Cent O S. While Americans can get away with "Scent Arse" among themselves it would be inadvisable to use this expression elsewhere if you wanted to be taken seriously. I have been automatically pronouncing it "Sentoss", as it looks Greek and I always get the "C" wrong - if it were Greek it should (I think) be "Kentoss". "Cent" as a prefix has at least 2 meanings, the number 100 and the root of Centre, my Shorter Oxford has columns full of words derived from them. I think it is a good name, it has a classical grandeur, it is short, it is not likely to be confused with anything else, and there will be relatively few variant pronounciations outside of local dialect differences. But who cares how you say it if it boots?
Pessoalmente, eu o pronuncio Cent-OS . Como você pronuncia, depende de você: as pessoas entenderão o significado da distribuição, independentemente da maneira como você a pronuncia ( ou, se não, provavelmente é hora de ver um fonoaudiólogo:))