Guetzli means cookie in Swiss German, I wonder what inspired the devs to choose that name
Also popular Swiss pastry.
Basically you can add -li to almost any word in swiss german and there are lots of words already which end with -li. It's a way to make a word sound "cute".
As an example, "Auto" means car, but if we call it "Autöli" it means that it's either a toy car or just a little(,cute) car :)
It was aiming for better compression than LZ4 at much higher speeds than deflate. Now brotli and zstd on their faster settings mostly beat it in that niche.