Ambient bus arrival monitor from hacked Linksys WRT54GL. Transport for London has a wonderful service called Countdown that can give live bus arrival times. For example, here's a page showing live buses passing No. 10 Downing St. Underlying this is a simple JSON API that, while not public, seems to be usable by the average programmer. So with its details deciphered (hardly hard since the web site uses the API) John Graham-Cumming set about building an ambient bus monitor into a model London bus. The idea is to glance at the model bus and see the times of the next two real buses you're likely to want to catch, and know when to leave the house.
What the Heck is Shadow DOM? Browser developers realized that coding the appearance and behavior of HTML elements completely by hand is a) hard and b) silly. So they sort of cheated. They created a boundary between what you, the Web developer can reach and what’s considered implementation details, thus inaccessible to you. The browser however, can traipse across this boundary at will.