The JavaScript Execution Context & Stack
davidshariff.com
davidshariff.com
And this guy creates "stunning applications & designs used by millions of people"?
I suspect from the technical nature of the article he is a front-end programmer and not a designer, and from the display issues I would guess he works in a large enough team that he rarely has to worry about front-end design as someone else is responsible for that.
And his site suggests either he is not very good at it, or he is comfortable enforcing what he believes the web is on the visitors to his site, i.e. minimum browser canvas width of about 1200 pixels. At that point the pseudo-left-hand menu doesn't obstruct the content.
I'm surprised that an 'in-depth' article completely ignores closures and the peculiarities of their execution stack.
[edit]: FWIW, here's a more detailed explanation about all this that seems very straightforward and complete (from 2004). http://jibbering.com/faq/notes/closures/#clIRExSc
However, the tweet thing on the right still annoyingly moves around, and the bar on the left still scrolls with the page.
It's stunning from how annoying it is, and lets not forget that Craigslist is also a design used by millions of people, so his assertions don't automatically mean he is a great designer, although I prefer the simple if cumbersome design of Craigslist to an annoying jumping sidebar.
A joke is more like "Knock, knock. Who's there?" etc.