In Firefox there is a menu item that displays “Page Source”: View | Page Source (Ctrl+U).
In Internet Explorer there is a similar function.
When you invoke it, it displays a nicely formatted and syntax-highlighted collection of HTML (and JavaScript) code.
What I don’t know is whether this HTML (viewable in the Page Source) is the result of pre-processing of the JavaScript (resulting in modification of the original raw HTML) or just raw as received by HTTP GET.
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.