This isn't a million miles from what you get with Javadoc + Eclipse, where if you hover over an item you see the snippet of Javadoc attached to it where it was

This isn't a million miles from what you get with Javadoc + Eclipse, where if you hover over an item you see the snippet of Javadoc attached to it where it was defined (i.e., in some other sourcefile, or jar). A few key points that make this useful: The documentation snippets are attached to specific methods, parameters, classes, etc - like in Javadoc or Doxygen. You don't have to wade through stuff you care about to find out about the the thing you care about (under your mouse).