Hello What type if design is these websites using ? Google, Facebook, Yahoo, Youtube, Wikipedia thanks
What do you mean? You want to know the design concept like parallax or do you think their "theme" might be available for purchase?
What do you mean "Type of design"? It's pretty obvious when looking at the pages, isn't it? Or do you mean the underlying design, ie what is running the pages? Google, Facebook, Yahoo and YouTube are custom coded, mostly the underlying code is pretty horrible, and contains a LOT of javascript. Wikipedia is run on a wiki - I dunno if the exact version Wikipedia is using is up for grabs, but since it's an open source project, I assume it is.