There are a couple of sites that have shopping carts
that I like (we're looking to upgrade our Shopsite
installation). But... for the life of me I can't figure
out what carts they're using.

They are:

https://www.roadrunnersports.com/
http://chefscatalog.com/

Can anyone tell me what carts they're using (different
carts). I particularly like the Chef's Catalog cart.

We'd stick for a while longer with Shopsite, but it's got
a couple of (small but important) show-stopping issues
as we get larger:

- no ability to specify shipping weights for sub-products
- no ability to track inventory for sub-products

By sub-products I mean product options, such as sizes
or colors for a shirt.

Anyway, if anyone can help with the cart identification,
I'd appreciate it. And if anyone has particular cart
recommendations, I'd appreciate it.

We're looking for something full-featured and preferably
that's part of a complete real-time inventory system (or
at least that can be integrated with one).

Thanks much.