Markup.io isn't actually a part of the world-wide web of linked semantic documents. Its content is inaccessible (even for viewing) unless you blindly trust its

Markup.io isn't actually a part of the world-wide web of linked semantic documents. Its content is inaccessible (even for viewing) unless you blindly trust its code. It rightfully deserves to be a browser plugin, it's just cleverly smuggling itself into everyone else's content because there are no good portable extension mechanisms for browsers.