The Acharnians (Greek: Ἀχαρνεῖς) is the oldest surviving play by Aristophanes and thus the oldest extant comedy in the world. It satirises the plight of rural Athenians during the early Peloponnesian War, through its central character Dikaiopolis, who concludes his own private peace treaty with the Spartans.
Free online texts
Gutenberg: The Acharnians. English translation, HTML format.
Internet Archive: Aristophanes I - Acharnians, Knights, Clouds, Wasps. Greek text and English translation. Public domain Loeb edition, multiple formats.
Internet Classics Archive: The Acharnians. HTML and TXT formats.
Loebulus: Aristophanes I: Acharnians. Knights. Clouds. Wasps. Greek text and English translation. PDF of public domain Loeb edition.
Poetry in Translation: Acharnians, translated by George Theodoridis. Multiple formats.
University of Adelaide (Internet Archive): The Acharnians. English translation, HTML format.
History of Ancient Greece: o54- Old Comedy and Aristophanes. Podcast by Ryan Stitt.
Librivox: The Acharnians (Billson translation). Public domain audiobook.
Wikipedia: The Acharnians.
The Great Conversation: Further reading at Tom's Learning Notes
Aeschylus - briefly mentioned with respect in the play.
Euripides - satirised here as in many of Aristophanes' plays.
Herodotus - several passages are thought to allude to Herodotus' work.
Thucydides - Our best source for the political events which provided the occasion for Aristophanes' satire.
Ancient Greek resources: Learn to read Greek classics in the original.