How do they do it?

Lately i’ve been noticing some interesting stuff going on… for example look at -> http://finance.yahoo.com/ on the left side you’ll find “Market Summary”

1.) When you move your cursor over a stock name, it automatically expands, how’s it done ?

2.) When you click on Europe, US or Asia the entire content changes, …bummer. :block:

And i’m amazed what’s going on @ http://edition.cnn.com/

For example the Video navigation in the top right corner. How does it scroll like that without flash ?