At the least, I cannot find any mention of the specifics anywhere on the main GitHub page - this is the best that I can tell: http://facebook.github.io/react/docs/top-level-api.html#reac... . I do know the recommendation is to use JSX, and I can see why, but more visibility of the API would be better.

Edit: As a note, I did find out how it worked by doing source code diving two months ago.