This book describes the most interesting features of over fifty of the world's major languages and language groups.

The Oxford Essential Dictionary of Foreign Terms in English
A comprehensive reference on the spelling, history, and usage of thousands of foreign words and phrases used by English speakers for from more than forty languages

Using data from the U.S. 2000 Census, this site offers interactive mapping to show the density of speakers of thirty-seven languages and language groups.

a guide to the writing systems and languages of the world.
It also contains tips on learning languages, language-related articles, quite a large collection of useful phrases in many languages, multilingual texts, a multilingual book store and an ever-growing collection of links to language-related resources.

An encyclopedic reference work cataloging all of the world’s 6,909 known living languages