Can anyone please tell me what software, platform, code or whatever it is called I will need to build a similar site as examples below ? they are net really forums as they have carts ? made-in-china .com , fuzing. com , alibaba .com , tradekey .com
Joomla is the best platform to make such complicated web sites as there are many applications that come as plug-ins. For example, if you need to have a shooping cart, osCommerce can be used in combination with Joomla. I think it is the best starting point for you.