OpenWindows Advanced User's Guide Choosing Between Fixed and Proportional Fonts

Note that the default font displayed in Command Tool and Shell Tool is a proportionally-spaced font. Although this font is pleasing to the eye, problems occur in character alignment (when spacing and tabbing) with any proportionally-spaced font in terminal windows. If the spacing and tabbing character alignment are a problem for you, it is best to choose a fixed-width font for these windows. In the examples that follow, only fixed-width fonts are used for terminal windows; the examples for other windows and headers use proportionally-spaced fonts.