Öhrli actually. It maddens me to no end that they pick words which contain umlauts and then leave them out.

On the one hand it makes it easier for non-umlaut people and it makes their names unique, when googling for zopfli und brotli it pointed me to the github repos very quick.

Öhrli is actually the swiss german diminutive of Ohr (ear). Swiss german uses -li a lot for diminutives, whereas standard german uses -chen or -lein, the vowel of them stem is turned into an umlaut Ohr -> Öhrli/Öhrchen/Öhrlein.