Rashi

11th-century commentary on Pirkei Avot attributed to Rav Shlomo Yitzchaki, acclaimed commentator on Tanakh and Talmud.

Bartenura

16th-century commentary printed in most editions of the Mishnah, including summaries of talmudic discussions and legal conclusions.

Rabbeinu Yonah

13th-century commentary on Pirkei Avot by the author of Shaarei Teshuvah.

Rambam

Maimonides’ first published work, which he began writing in 1161 at the age of 23, including discussions on the Mishnah and legal decisions.