ZhongWen web app
This app is built using:
I tried implementing HTML 5 canvas-based stroke input using code from [http://jabtunes.com/notation/chinesestroke.html] but it found the matching algorithm to be too poor for non-trivial characters. You can see how far I got by checking out the canvas_stroke_input branch in the repo.
For now you can input pinyin or mandarin characters directly if you have a Chinese input support installed for your keyboard.
Tested on desktop (Chrome, Firefox) and mobile (iOS, Android).
Blog post: link
GNU Affero GPL v3 (see LICENSE.txt).