16. The system of claim 15 , wherein the zoom manager, in determining the desired number of characters per line to display, is operative to set the desired number of characters per line between fifty and seventy-five.
15. A system for displaying text within a document for readability, comprising: a processor and a computer-readable memory; an operating environment stored on the computer-readable medium and executing on the processor; and an zoom manager operating under the control of the operating environment and operative to: access a document comprising text; determine a display size for displaying the text; determine an average character width by computing an average of font widths used in the document; determine a desired number of characters per line to display per column; determine a first number of columns used to display the text based on the average character width, the display size and the desired number of characters per line to display per column; display the text in the determined first number of columns within a window that approximately averages the desired number of characters per line per column; and change at least one of: a zoom level of the document, a font size of the document, and the display size for displaying the text; based on the at least one of the changes, determining a second number of columns to be displayed such that the desired number of characters per line to display per column is maintained; and displaying the text in the second number of columns.