Glagolitic is a term that relates to a script system used in medieval Slavic languages, primarily for writing Old Church Slavonic texts. Some synonyms for the word Glagolitic include ancient Slavic script, Old Bulgarian script, and Cyrillic script. Cyrillic script is a writing system used for different languages across Eastern Europe, including Bulgarian, Serbian, and Russian. The Glagolitic script was developed in the 9th century by two Byzantine brothers, Saints Cyril and Methodius, who were missionaries to the Slavic peoples. This script has been an essential part of Slavic cultural heritage for centuries, and it is still studied and researched by scholars today.