HTML5 Canvas

http://simonsarris.com/blog/225-canvas-selecting-resizing-shape

http://shifteleven.com/articles/2012/01/08/mouse-clicks-for-html5-cavas-entities-via-paths

http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#drawing-rectangles-to-the-canvas