Is "Page Source" BEFORE or AFTER JavaScript has been rendered?

Unfortunately, it will always display the HTML as the page was before DOM-change by javascript, etc. So the answer is: what you are seeing is "raw as received by HTTP GET".

You can use a tool like Firebug (Firefox & Chrome) to see live dom changes. Or you can make your own function to display the live dom.

The "View Source" code is the code before any JavaScript is applied.

Firefox's Web Dev toolbar will allow you to view the resulting post-JavaScript source code from the View Source > View Generated Source menu option.

Before. The page source is the result of the GET request by the browser sans headers. If you want to view the updated content after scripts and so forth, you'll have to use a tool like Firebug or the Web Development toolbar.