It was introduced in the 16th century by Gian Giorgio Trissino[1] to represent the pronunciation of the "open e" (the letter e pronounced as the open-mid front unrounded vowel) in the Italian language; this use of the letter has since become the standard in IPA notation[1] (see § Use in phonetic alphabets, below).

Since the 20th century, the letter also occurs in the orthographies of many Niger–Congo and Nilo-Saharan languages, such as Ewe, Akan, Lingala, Dinka and Maasai, for the vowel [ɛ] or [e̙], and is included in the African reference alphabet.

Some authors use ƹayin ⟨ƹ⟩ instead;[citation needed] both letters are similar in shape with the Arabic ʿayn ⟨ع⟩.

The International Phonetic Alphabet (IPA) uses various forms of the Latin epsilon: The Uralic Phonetic Alphabet uses various forms of the Latin epsilon:[3] Akan, Bambara, Baule, Dagbani, Dogon, Douala.

Ewe, Fante, Frafra, Fon, Ga, Jula, Kabiye, Kpelle, Kuya, Lingala, Loma, Mende, Moore, Soninke, Twi, Vai.