The epistle of James.

One canonical catholic epistle.

Attributed author(s).
James.

Text(s) available.
Epistle of James 1-5 (on site, Greek only).
Online Greek Bible (Greek only).
Bible Gateway (English only).
HTML Bible: James 1, 2, 3, 4, 5 (Greek and English).
HTML Bible: James 1, 2, 3, 4, 5 (Latin Vulgate only).
Zhubert (Greek and English).
Kata Pi: James 1, 2, 3, 4, 5 (Greek and English).
Sacred Texts: James 1, 2, 3, 4, 5 (polyglot).

Useful links.
James at the NT Gateway.
James at Early Christian Writings.
James by Daniel Wallace.
James in the Catholic Encyclopedia.
James at Kata Pi (R. M. Grant).
ECW e-Catena: James 1, 2, 3, 4, 5.

Only one canonical epistle is attributed to the figure so prominent in the early church that the bare name of James suffices to identify him.