 Another way to say this is that empty space in the frame actually denotes space, not (as in many text editors) just the absence of content.Frames being fixed in size scrolling as a form of interaction is eliminated (as the designers felt that scrolling is suboptimal) opting instead for larger aggregates such as documents and programs to be structured as hierarchies (or more generally, lattices) of hypermedia nodes.This flexibility makes it possible to create a document, search, run programs from a tree of frames starting at any frame.