for osCommerce Online Merchant v2.2
Retina Images serves different images based on the device being used by the viewer.
Once setup on your website (very simple!) all you have to do is create a high-res version of each image you would like optimized for retina screens and all the work is done for you. You don’t even need to change any <img> tags (providing they have a height or width).
This should be compatible with OSC2.2+ and sites that are viewport optimized.
This is based on the work done by Jeremy Worboys over at http://retinaimag.es/