1. Duolingo.com – Duolingo offers six languages with grammar and vocabulary lessons. Earn points and unlock levels as you go along.
2. Memrise.com – Learn vocabulary through spaced repetition.
3. Anki – Anki is a flashcard program similar to Memrise with hundreds of decks.
4. BBC Languages – The BBC offers lessons with grammar, vocabulary, games, activities, and tests in forty languages.
5. Livemocha.com – Online courses for over 35 languages.
6. Lang-8.com – Write in your new language and have a native speaker correct your mistakes.
7. Babbel.com – Learn languages by identify correct translations.
8. Lingocracy.com – Choose the content you want to read, and get instant translations and definitions.
9. Babadum.com – A vocabulary quiz game.
10. InternetPolyglot.com – Lessons and games for learning languages.
11. Verbling.com – Teach someone a language, and they will teach you one.
12. Interpals.net – Find a pen pal from another country and learn their language.
13. SharedTalk.com – A community of people from around the world dedicated to language exchange.
14. Coffeestrap.com – Learn a language by meeting people.
15. FSI Language Courses – These are courses developed by the U.S. government that have reached the public domain. Download the text and repeat after the tapes.
16. GreatLanguageGame.com – A game where you try to distinguish between eighty different languages.
17. Forvo.com – Get correct pronunciations of thousands of words in dozens of languages.
18. LyrnLang.com – Learn words and phrases by listening to songs and seeing how the lyrics translate.
19. Lernu.net – Free courses and information on the international language of Esperanto.
20. Chineasy.org – Lessons and resources for learning Chinese.