TotalTerminal is a plugin for Terminal.app. It provides persistent Visor Window which slides down when you press a hot-key.
Page One meanwhile leaves the site design in place (in most cases), letting you see the article’s entire content without breaking from the site’s browsing experience. You don’t have to take any action to trigger Page One’s functionality, either. It makes its changes silently so that you’re getting full content as part of your casual browsing.