This is a free website that is also available as an iPhone or Android app. It offers free lessons in over a dozen languages, including Spanish, French, German, Italian, Russian, Irish, Dutch, Turkish, and more. New languages are continually being developed.
This site brings together information about ancient languages, with links to dictionaries, classic texts, and other language-learning tools. It includes Arabic, Aramaic, Egyptian, Gaulish, Gothic, Hebrew, Hittite, Old English, Sanskrit, and more.
This site brings together free language-learning materials for over a hundred languages. These materials were developed by the Peace Corps and the U.S. State Department. The site also offers Skype lessons in several languages, but there is an hourly charge for those. We recommend just using the free stuff!
This site includes hundreds of language-learning courses. Most languages have multiple courses designed for different levels of knowledge or for different situations in which you might use the language. Within each course, words are repeated to build your memory, and words are both spoken and displayed on the screen. There is a deluxe version you can purchase, but much of the content is totally free; all you have to do is make an account or sign in with Facebook or Google+.
This site brings together general information on many different Native American languages. It also includes information about different tribes' cultures and traditions and other recommended websites and books.
This site brings together recordings of native speakers reading through word lists in their own languages. Each recording has an accompanying word list you can follow as you listen to the recording. There are recordings of many endangered languages from around the world, including Native American languages.
