From where can I get osCommerce v2.3.1 documentation because the link from the site is not working?

Zen Cart is built from the osCommerce system... and osCommerce sucks. That's WHY zen cart was built... convince your client to use Zen Cart. It's better.. and there is way more support for it... here's a website that has a ton of free zen cart templates. a href="http://www.templatezencart.com" rel="nofollow"http://www.templatezencart.com/a If you wanted to, you could just look at how the templates are set up, using the templating system. It's really easy.