Two documents are processed to facilitate visual mapping and comparison. These documents comprise document subsections and the subsections comprise document subsection headers associated therewith. At least one of the first document subsection headers is juxtaposed relative to an output of second document subsection headers mapping thereto, to visually emphasize a header mapping. This header mapping is established by: mapping the first document subsections relative to the second document subsections based on identifying substantial similarities therebetween, to establish a subsection mapping therebetween; and, in relation to the subsection mapping and the association between the document subsections and the subsection headers, further mapping the first document subsection headers relative to the second document subsection headers. Several closely-related devices, systems and methods for outputting information to compare at least two documents, establishing a mapping to compare at least two documents, and highlighting similar text segments, are also disclosed.