This site contains a huge number of lessons, complete with texts, vocabulary, audio, exercises and much more. And it's all free. Note that if you want to get the intermediate and advanced material,... Read more.

collections.uiowa.edu

Finally, Duolingo added a En->ZH course. As Duolingo is the most popular gamification learning app, the learning experience is relatively streamlined and tested. The monetarization aspect leads to ... Read more.

en.duolingo.com

This page offers several hundred lessons for Chinese about different topics, including both reading practice and listening. They also have some learning activities, including quizzes. I have tried ... Read more.

gloss.dliflc.edu

The Chinese Language Institute (CLI) offers free Mandarin learning resources in the form of articles on a variety of topics including Chinese characters, Chinese grammar and chengyu. They also offe... Read more.

studycli.org

ChineseMe is the most integrated Mandarin course, designed for motivated learners who have decided to become fluent. It is an interactive textbook that adapts itself to your interests. The course i... Read more.

chinese-me.com

A London-based school that takes their Mandarin courses to the next level - integrating technology (bespoke Phone Flashcards) and HSK test planning into their courses from Beginner, Intermediate to... Read more.

practicalmandarin.co.uk

From their website (if you have personal experience of their courses, please leave a comment): New Concept Mandarin specializes in teaching Mandarin Chinese (Putonghua) as a second language. Act... Read more.

newconceptmandarin.com

Hanbridge Mandarin provides campus-based courses, online classes, and intensive cultural immersion programs. I don't know anyone who has attended any of their classes personally, but they cover the... Read more.

hanbridgemandarin.com