Cool Ruler is a practical screen ruler born to help measuring in jobs like web page creation and graphics design. It can be placed horizontally or vertically on the screen, allows to adjust length freely, supports for multiple tags & units (including the customizable units). To some extent, it can improve the work efficiency of designers.

PixelWindow is easy to use, lightweight and cross-platform (thanks to Adobe AIR) transparent screen pixel ruler, with which you can measure anything on your screen, especially for designers.