http://www.pocketpcinvoice.com/orders/browse_products.php

i've seen this shopping cart at many website, can anybody enlight me what is this shopping cart?

thanks.

1) expired SSL certificate on their website.
2) they are using custom written shopping cart.

I'm pretty sure it's not custom written cart.

how about one more example?

http://www.ihostdev.com/audit2/order/browse_products.php?category_id=6

That's not a custom cart, it's WHMAP v3. Go here and order the free package, and you'll see the same order form. There were references to an image named "autopilot" in the code, that's how I found it.
http://www.whmautopilot.com/purchase.php