Shopify is not open source. ActiveMerchant benefits Shopify by being open source because it allows third parties to write payment modules which can be folded in

Shopify is not open source. ActiveMerchant benefits Shopify by being open source because it allows third parties to write payment modules which can be folded into Shopify. Since Shopify's main competitors are written on php, asp and other non-ruby languages this amounts to a competitive advantage.