If you want to make your site adaptive/responsive, but you don't want to deal with confusing CSS media queries like @media all and (max-width: 699px) and (min-width: 520px), then Adaptivate is for you. By including this jQuery plugin, you'll get dynamic classes like "width_lt_640 width_gt_480 width_eq_520 orientation_portrait". You can then target these in your CSS to have different styles for different browser window sizes.