I think you're being downvoted not for your question per se, but because the point of the link is not "hey look at this neat tool we made called Coq", but rather "hey look we formally verified C11". Coq has been around for probably close to 20 years.

Side note – "Coq" is chosen because it is based on the calculus of constructions, whose abbreviation is "CoC", and whose creator's last name is "Coquand".