Aristophanes of Byzantium, a Greek scholar, critic and grammarian, particularly renowned for his work in Homeric scholarship, but also for work on other classical authors such as Pindar and Hesiod, had moved to Alexandria when young and studied under Zenodotus and Callimachus.

He had succeeded Eratosthenes as head librarian of the Library of Alexandria sometime in the late 190s BCE at the age of sixty.

Aristophanes is credited with the invention of the accent system used in Greek to designate pronunciation, as the tonal, pitched system of archaic and classical Greek was giving way (or had given way) to the stress-based system of koine.

This is also a period when Greek, in the wake of Alexander's conquests, has been a lingua franca for the Eastern Mediterranean (replacing various Semitic languages).

The accents have been designed to assist in the pronunciation of Greek in older literary works.

He has also invented one of the first forms of punctuation; single dots (distinctiones) that separate verses (colometry), and indicate the amount of breath needed to complete each fragment of text when reading aloud (not to comply with rules of grammar, which would not be applied to punctuation marks until several centuries of years later).

For a short passage (a komma), a media distinctio dot is placed mid-level (·).

This is the origin of the modern comma punctuation mark, and its name.

For a longer passage (a colon), a subdistinctio dot is placed level with the bottom of the text (.), similar to a modern colon or semicolon, and for very long pauses (periodos), a distinctio point near the top of the line of text (·).

Aristophanes dies in Alexandria around 185-180 BCE, and is apparently succeeded as chief librarian by his pupil Aristarchus of Samothrace, a grammarian noted as the most influential of all scholars of Homeric poetry.

He establishes the most historically important critical edition of the Homeric poems, and he is said to have applied his teacher's accent system to it, pointing the texts with a careful eye for metrical correctness.

It is likely that he, or more probably, another predecessor at Alexandria, Zenodotus, is responsible for the division of the Iliad and Odyssey into twenty-four books each.