I search for next option:
We want to develop main site, who give the option to his users (who registerd) to open sub-stores under our main store.
I saw the option of multi-store on Magento,Shopify, Opencart, Wordpress and so… but i dont sure if it answer my question.
If there is somthing that do what we serach – i will be happy if there is also ready theme for it.
Not possible to achieve this with an open source system. At least not exactly the way you described it.
Anyways, with opencart you can have multivendors system that allows users to upload and sell their own items, but not really create a separate shop.
May be the other systems have similar features too – not sure.
Hope this helps.