The second book of the Khuddaka Nikáya of the Sutta Pitaka.
It is probably a later anthology than the Thera-Therí-Gáthá, and its earliest mention by name is in the Milinda-pańha (p.408).
It includes gáthas collected together from various books in the Canon, but contains hardly any from the Játaka collection, or directly derived from the Sutta Nipáta.
The present text of the Dhammapada contains four hundred and twenty-three verses divided into twenty-six vaggas.
So far, five recensions of the Dhammapada have been discovered. (For details see Law: Páli Lit., pp.215f).
A commentary on it exists called the Dhammapadatthakathá.