Instantaneous word counter

Instantaneous word counter

I'd like to add a word counter to a large text box (think blog editor)
that increments with every word that I enter. (i.e. after I type "Hello"
it would increment from 0 to 1 and after I write "world" after that it
would increment to 2). I'd like to do this within a webpage but I'm happy
to consider other options.
I have no idea how to do this. I think there would be a way to do this
with Javascript but I know next to nothing about Javascript.
Could someone point me in the direction of figuring out how to do this?