Designers have been playing with interfaceless, or "chromeless," browsing for a long time, and users have recently started seeing hints of it in commercial software. Any browser with a full-screen mode becomes temporarily chromeless and Apple's latest version of Safari, while it maintains a menu and title bar, is without chrome on three sides. Many mobile browsers are nearly or, in the case of Windows Phone, are completely without obstructing interfaces. The latest version of Mac OS has been almost entirely rid of persistent scroll bars, and ancient and essential bit of chrome.
Mozilla Labs' Chromeless Browser/Webian project, which looks abandoned, was a chromeless browser for the desktop. The lack of a few interface elements in a browser might seem like a small change, but the experiential difference is large: when a website doesn't feel like it's nested within an app, it becomes an app. And when you interact with it primarily with mouse or touch gestures, rather than through soft buttons, it becomes something even better than an app.