Microsoft Site Server as a prevalence system

"Microsoft's Site Server Commerce 3.0 (perhaps earlier/later versions as well, but I haven't used them) employed a similar model: using a collection of COM components one would (de)serialize the shopping cart using to a table in the database. You would simply deserialize the shopping cart, add/update/remove fields, and serialize the shopping cart again. When an order was placed it would again deserialize the shopping cart and pass it off to a chain of responsibility'esque handler that would run (in|out)side of MTS called a "pipeline." Using another collection of COM components one would have the header and detail information for the order inserted into the appropriate tables as individual records." [Chad Osgood]

Interesting. Aside from reading a few articles on it I have no experience with MS Site Server. Is anybody still using it in production?