Evaluate MathQuill MathFields via the Wolfram|Alpha API

MathQuill-Evaluate builds on MathQuill, and gives you basic
capabilities for evaluating the expressions that users enter into your
MathFields. Just pass your MathField as an argument to the evaluate function,
and get a solution back.

MathQuill-Evaluate does this by passing the LaTeX from your MathField to
Wolfram|Alpha. Wolfram|Alpha has the
ability to evaluate arbitrary LaTeX and return either a simplified expression
or a solution.

The Wolfram|Alpha API is just awful, but I managed to make it cooperate
a little bit. However, this isn't the stablest of projects right now. If you're
trying to evaluate anything seriously, I'd recommend building your own, more
robust solution, but this will work in many trivial cases.

Try it

This is a live example. This example displays LaTeX as you type, and then
when you press "Evaluate", that LaTeX is sent to Wolfram|Alpha. After a few
seconds, you should see a response.