EarthFluent

Social Learning: You can comment on lessons or languages or words, and you may also like or dislike them.  Join the conversation with the others.

Fresh Content: Images used in lessons are from image search engines, so this means fresh, more amusing content.  The gallery of images for "cow" contains a cow wearing a blond wig.

Accurate Audio: Audio is provided by the well-supported, regularly-updated Chrome Voice-Synth module.  But all you need to run it is the Chrome browser.

Free: Thousands of lessons, but not one penny is required.  Learn in Spanish, French, Italian, German, Japanese, Chinese, Hindi, Indonesian, Dutch, Polish, Portuguese, Russian, or Korean.

Open Source: Developed openly by the Community, under the title of the GreenGluon CMS, on GitHub.  Want a new feature?  You can make it yourself.

All freely available here : http://www.earthfluent.com/