It was not an easy job to do! But finally I got my Marvikshop online.
My old webshop was an Oscommerce shop and I got some Joomla sites online.
The main thing to choose for MarvikShop is the database. It's the same as Oscommerce. So I just had to copy my old database to the new Marvikshop.
I use MarvikShop 2.2 with Joomla 2.5.1 for my webshop.
MarvikShop itself got a lot add-ons. Maybe a little too much. Not all of them works correctly. But the basic Oscommerce functions works fine. A lot information you can find on the original Oscommerce website. For now, I think Marvikshop is the most advanced webshop for Joomla online.
It is nice to see that every new version of MarvikShop, got's a lot problems solved. I know it's not an easy job to do. MarvikShop is almost one year old. I hope the integration of MarvikShop with new Joomla versions will still be fine in future.