[jQuery] How does $(document).ready() work?

[jQuery] How does $(document).ready() work?


I am working on a project where using jQuery's $(document).ready()
would be extremely useful, but unfortunately I cannot use jQuery.
I found this page on determining when a document's DOM is ready:
http://www.javascriptkit.com/dhtmltutors/domready.shtml
Is this how jQuery does it?
Thanks!
- Jim