Treebanking is simply the act of writing down your interpretation of a sentence in the form of a linguistic annotation. All of it can be done online, and over 200 researchers from around the world have annotated more than 350,000 words of Classical Greek and Latin texts, including the entirety of Homer's Iliad and Odyssey, all of the works of Hesiod and Aeschylus, Sophocles' Ajax, and excerpts from the works of Caesar, Cicero, Jerome, Ovid, Petronius, Propertius, Sallust and Vergil.