The List of Popes - - In chronological order. Links to a biographical essay on each pontiff up through Pope St. Pius X (d. 1914), from the 1913 Catholic Encyclopedia.
Papal Encyclicals Online - - Archive of encyclicals and other papal documents. Fairly complete from Pope Gregory XVI (1831-1846) to the present; some documents from earlier popes, as far back as Honorius III in 1227.
Popes of the Roman Catholic Church - - A table from The Columbia Encyclopedia, 6th ed., in chronological order. Some entries linked to biographical articles.
Popes Through the Ages - - By Joseph Brusher. Papal lineage table, and brief accounts of the pontificates of every bishop of Rome from St. Peter the Apostle to the present.