We are making Skritter, a web application for students of Chinese (and Japanese) to learn characters and vocabulary through written practice. We are developing stroke-level handwriting recognition algorithms that will give instant and specific feedback on the characters that users write, as well as an intelligent learning system that will manage their vocabulary and select characters for them to learn and review.
Once we have a great app for learning the writing of Chinese characters and Japanese kanji, we can branch out into non-character-intensive languages, as well as into listening, speaking, and reading.