A website on the etymology of Chinese characters, with a lot of images of their past forms from different periods. Read more.

chineseetymology.org

Ninchanese is a complete way to learn Chinese. Its online course allows you to learn and practice how to read, write, speak and understand Chinese in an enjoyable manner. It combines game mechanics... Read more.

ninchanese.com

This is the best overview of spaced repetition research I have seen online or offline. It's thorough, well-argued and probably covers more than you were looking for. It's not specifically about Chi... Read more.

gwern.net

You can input Charakters and this tool will output statistics about the words and characters, and can suggest high frequency words and characters that should be learned. It also analyses the HSK le... Read more.

hskhsk.pythonanywhere.com

The stories behind the names of all of China's provinces and autonomous regions. Read more.

online.thatsmags.com

A program to split any Chinese text into individual words, summarizing information about each unique word. The information is presented in the form of a tab-delimited matrix, so that the results ca... Read more.

zhtoolkit.com

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

Online Chinese flashcards that adapt to your learning, Chinese speaking practice using voice recognition, and a simple, fast Chinese-English dictionary. Read more.

fastchinese.org