Linguistics & languages websites
Center for Applied Linguistics - Nonprofit organization working to improve communication through better understanding of language and culture
Ethnologue - An encyclopedic reference work cataloging the world's known living languages; provided by SIL International
Glossary of Linguistic Terms - Provided by SIL International
The International Phonetic Alphabet - Provided by the International Phonetic Association
MLA Language Map - Map of languages spoken in the U.S.
Speech Accent Archive - Provided by George Mason University, this resource lets you compare accents of English speakers
Language learning websites
Defense Language Institute - Provides a number of free online tools for learning language and cultural skills
GLOSS - Online language lessons developed by the Defense Language Institute. Reading and listening lessons based on authentic language materials in 24 languages.
Language Course Finder - Find language schools and language courses worldwide
American Sign Language Browser - This Michigan State University resource is a video dictionary of thousands of ASL signs
Lexicool - A collection of bilingual and multilingual dictionaries
Oxford English Dictionary - a historical dictionary of the English language from the earliest times to the present day; shows not only the current meanings of words, but also traces their development through time.
Wordnik - This interactive English dictionary includes definitions, examples of use, photos, etymology, and more.