I am a native English speaker and had no idea that nginx was supposed to be a cutesy spelling of "engine-x" until now. I've always imagined it pronounced like the speaker had a mouthful of pebbles, something like 'n-g'n-ecks.
Until about three weeks ago I had no idea one of the engineers on our team was even talking about the web server/engine component when he was talking about "Engine X" and as far as I could tell we were using something called "N Jinx".
A lot of cross-purpose conversations were had. I assumed he had written some component of his own called engine X.
Likewise. I've always just spelled it out when I read it in my head.
Now I need to figure out imgur, since it's apparently more clever than "image-ur". im-gur? image-ur... imager? Is it supposed to be "imager"? I'm clueless.
I always though nginx was some variant of Vogon. It /never/ occured to me to pronounce it "Engine X". I've heard other people mention Engine X and never made the connection.
What does nginx stand for? Engine X?
SPDY and nginx are short and memorable and carry a notion its authors wanted them to associate with (either speed or "being an engine".)
As an anecdotal data point, I must say I'm not a native English speaker but understood both names the first time.
From an accessibility standpoint though, I wish we could do better.