Researching an ecommerce platform. I'm wondering if you can tell me
using only a url string, what type of online shopping software some of
these companies are using.

I'm seeing /wcs/stores in many a top brand name online url. If you
google search 'wcs/stores/' you'll see Ikea, Staples, Lenovo,
Panasonic, etc, etc.

It must be a pretty common shopping enging that they are using. Could
you possibly tell me who the vendor is?

For example most osCommerce stores have 'osCsid' in their url string.
Wondering if you can use wcs/stores to come up with the same type of
answer.

check out this link
http://www.internetretailer.com/top500/

I get their magazine and find it useful (and free). This guide they
sell details the vendors used by a lot of the largest internet
companies. I havent bought it, however it may have what youre looking
for.

WebSphere Commerce