A tool that lets you paste your working WebKit, Mozilla, or IE10 keyframe animation code and then output the rest of the necessary code, including the standard syntax.
The app requires that you use working code that uses a single vendor prefix, and you must specify via a radio button which one you're entering (i.e., it won't auto-detect).
You can view a screencast explaining the tool here: http://www.youtube.com/watch?v=araO0Vli-j4