Very cool service called TonicDev which allows you to embed a Node.js runtime into a webpage and analyze the object properties.
Here is a test of a simple embedded tonic environment.
For fun, here is another example of an embedded codepen that I made while designing my first blog.
And here is another example of my embedded editor:
<p> <pre>Hello, hello</pre> <pre style="color: blue;">Hello, hello</pre> <p>