Zenodotus was the first superintendent of the Library of Alexandria and the first critical editor of Homer. In 284 BC the Ptolemaic court appointed Zenodotus as first Director of the library and also the official tutor to the royal children. His colleagues in the librarianship were Alexander of Aetolia and Lycophron of Chalcis, to whom were allotted the tragic and comic writers respectively, Homer and other epic poets being assigned to Zenodotus. Although he has been reproached with arbitrariness and an insufficient knowledge of Greek, his recension undoubtedly laid a sound foundation for future criticism. Having collated the different manuscripts in the library, he expunged or obelized doubtful verses, transposed or altered lines, and introduced new readings. It is probable that he was responsible for the division of the Homeric poems into twenty-four books each, and possibly was the author of the calculation of the days of the Iliad in the Tabula Iliaca. He does not appear to have written any regular commentary on Homer, but his Homeric γλῶσσαι probably formed the source of the explanations of Homer attributed by the grammarians to Zenodotus. He also lectured upon Hesiod, Anacreon and Pindar, if he did not publish editions of them. He is further called an epic poet by the Suda, and three epigrams in the Greek Anthology are assigned to him. In addition to his other scholarly work, Zenodotus introduced an organization system on the materials in the Library of Alexandria whereby texts were assigned to different rooms based on their subject matter- verse or prose, literary or scientific, and the various sub-classifications within each. Within their subjects, Zenodotus organized the works alphabetically by the first letter of the name of their author. The principle of alphabetic organization was introduced by Zenodotus. In addition, library staff attached a small tag to the end of each scroll. These tags gave authors' names as well as other identification had been added during the accessions procedure but often no title; many a roll contained more than one work, and many works, such as compilations of poetry warranted more than a single title. When a title was lacking, Zenodotus had to enroll and pass an eye over the text. Such tags enabled the scrolls to be easily returned to the area in which they had been classified, but also ensured that library users did not have to unroll each scroll in order to see what it contained. This was the first recorded use of metadata, a landmark in library history. Not until the second century A.D. does fuller alphabetization make an appearance.
