I am using Virtuemart as a mall, making the best of its skeletal multivendor features. What I want is to allow my vendors display their store on their own website - say in an iframe - such that their customers can register/login to the mall, browse, shop and pay without leaving their website. That is, my mall and payment gateway run in the background only

I am looking for an API plugin that allows users to pull and display all items in their store using the vendor id as a filter.

The user interface on the vendor's site should also allow for modules that display for vendor id-filtered categories, featured products, latest products, most popular products and of course a shopping cart. That is, these modules would display only categories that the vendor's products are listed, and on-click each link pull and displays the vendor's products in the frame on the vendor's site.

The plugin has to be platform independent (i.e. it can work in all environments - html, php, asp, whatever.