Example purchasing systems and methods are described. In one implementation, a method identifies a purchase request that includes a first item to purchase from a first merchant and a second item to purchase from a second merchant. A first virtual machine is invoked and executes an instance of a browser application to purchase the first item from the first merchant. A second virtual machine is invoked and executes another instance of the browser application to purchase the second item from the second merchant. The method receives a first purchase confirmation from the first merchant and receives a second purchase confirmation from the second merchant.