Busuu is a fast growing online language learning community with over a million users as of early October 2010. The site is named after a Cameroon language of the same name, which according to their website, is now spoken by only 8 living people! All in all, the site is very similar, in a good way, to LiveMocha (read my review of LiveMocha here). Both use a "freemium" model, offering both free and premium services, which is great for new users who want to get their language learning feet wet before committing to a monthly credit card charge. Both are social networks, relying upon and benefiting from crowd sourcing to correct user writing samples, provide conversation practice, etc. There are, however, many subtle differences between the two sites; some good, some bad...

With over 5 million registered users spread across 200 countries, LiveMocha is the world’s largest language learning community. And with sufficient venture capital and corporate partners behind them, the Seattle-based start-up firm has the resources to keep expanding their service...

Pronounced like the word "link" (not "ling-kyu" as it is often mispronounced), LingQ is an an online and iOS app based language learning system created by Steve Kaufmann. The "freemium" site allows users to easily look up and save unknown words and phrases (what they call "LingQing", hence the name of the site)m with tools for 11 languages: Chinese (Mandarin), English, French, German, Italian, Japanese, Korean, Portuguese, Russian, Spanish, and Swedish (which happen to be the same 11 languages Steve speaks).