While Esperanto orthography uses a diacritic for its four postalveolar consonants, as do the Latin-based Slavic alphabets, the base letters are Romano-Germanic. Ĝ is based on the letter g, which has this sound in English and Italian before the vowels i and e (with some exceptions in English), to better preserve the shape of borrowings from those languages (such as ĝenerala from general) than Slavic đ (Serbo-Croatian) or dž would.[1]
In Aleut, an Eskaleut language, ĝ represents a voiced uvular fricative/ʁ/. The corresponding voiceless Aleut sound is represented by x̂.
In Dutch, the letter ĝ is used in some phrase books and dictionaries for pronunciation help. It represents a plosive [ɡ], because g is pronounced as a fricative /ɣ/ in Dutch.
In some transcriptions of Sumerian, ĝ is used to represent the velar nasal /ŋ/.