All drawing and diagramming tools that we use to create wireframes are based
on shapes or widgets. You drag a widget from a palette and drop it onto the
page, then set its position and size with mouse. The operation is easier if
the editor supports snapping to the grid and guides.
I wonder however if this is the optimal way of drawing wireframes, because
it doesn't account for their peculiarities, namely:
* Content rectangles never overlap each other but cover the entire page
"real estate"
* Content rectangles are mostly aligned in columns and rows, i.e.